Vice President Kamala Harris has pulled slightly ahead in national polls against former President Donald Trump. Still, the race is pretty tight, and it looks like it will remain that way until Election Day.

Despite polling errors that overestimated Democrats’ performance in the popular vote in 2016 and 2020, head-to-head polls are still the best signal of what the election outcome will be — though it’s important to keep in mind that no single poll will be exactly right, and that some polls have better methodologies than others.

But head-to-head polling isn’t the only way to gauge the state of play. Other election indicators — ranging from approval ratings and sentiments among key groups of voters to economic measures and campaign spending — all provide crucial context about where the electorate and this campaign are headed.

Here are some factors beyond topline numbers that we think are especially crucial to help you gain a fuller understanding of the race.

President Joe Biden may have stepped aside from the Democratic nomination, but that doesn’t mean he’s irrelevant: Biden’s approval rating is a proxy for how voters feel about his administration — one whose record Harris has for the most part defended.

It would be a worrying sign for Harris if that number — which already made Biden historically unpopular before he dropped out — stagnates or goes down before the election.

That “would be a negative verdict on the incumbent administration, which she is part of,” said Kyle Kondik, managing editor of Sabato’s Crystal Ball, a nonpartisan political analysis newsletter, at the University of Virginia Center for Politics. “I wouldn’t take that as predictive on its own, but I do think the president’s approval rating still merits watching, even though he’s not a candidate anymore.”

Harris has so far managed to both take credit for Biden’s popular policies and decouple herself from his most unpopular policies. Her approval rating is about 42 percent, up from about 38 percent when Biden dropped out on July 21, according to FiveThirtyEight’s polling average. Biden, on the other hand, so far hasn’t gotten the kind of boost that many people thought he might after dropping out: His approval rating is only up about 2 percentage points to 41 percent.

That number could be a liability for Harris because “Republicans are gonna do their damage to connect all of the unpopular things with Biden to Harris,” Kondik said. “It’s just the question of whether it works or not. I don’t think it’s worked yet.”

For nine years now, more Americans have viewed Trump more unfavorably than favorably. But Trump’s favorability is also rising notably, suggesting that he has expanded his appeal.

That may be because the memory of his first term, when he was incredibly unpopular, has faded somewhat in the public’s consciousness. What voters may remember fondly is that the economy was doing well under his presidency until the pandemic hit. Other voters may just like that he’s not Harris or Biden.

“I think to some degree, independents have less of a negative association with him now that he’s out of office and has been for a while, and they weren’t really happy with the Biden administration,” said Lakshya Jain, a partner at the political forecasting firm Split Ticket.

Trump has maintained a strong base of support among Republicans, leveraging the numerous indictments against him to make the case that he has been targeted as an anti-establishment candidate. He’s also made overtures to moderates, including by somewhat dialing back the restrictive Republican stance on abortion.

At the same time, however, it would be wrong to say that Trump is popular.

“I wouldn’t say he’s cracked through a massive ceiling on favorability, because his negatives are still [high],” Jain said. Indeed, they’re currently more than 10 percentage points higher on average than his favorability ratings.

Whether these unfavorable numbers move as the campaign kicks into high gear in the fall and people get reacquainted with the former president remains to be seen. If they rise, that could signal trouble for Trump on Election Day.

Polls in battleground states suggest that Harris and Trump are practically in a dead heat. That means even the few percent of voters who remain undecided could tip the scales one way or the other. Keeping an eye on these voters will be key to understanding what to expect in each of the swing states.

That said, it’s hard to assess what way they’re leaning: Because there are so few undecided voters, pollsters often can’t get an accurate read on how they’re feeling. Demographically, they tend to be a bit younger and more diverse than the rest of the electorate, and they also tend to skew a bit more female. All of that would “suggest that Kamala Harris would have more upside with them,” said David Wasserman, senior editor and elections analyst at the Cook Political Report.

But that doesn’t mean Democrats should assume they now have an edge in swing states. These undecided voters also exhibit traits that might make them lean toward Trump. Wasserman said they are more distrustful of institutions and government, tend to work blue-collar jobs, have less than a four-year college degree, have broad dissatisfaction with the two-party system, and believe that the Biden administration has mishandled the economy.

“These are cross-pressured voters who may not turn out to vote at all at the end of the day, but that is a group that we’re watching closely,” Wasserman said.

Harris has shown the potential to improve with groups of voters who Biden had struggled with and are projected to play a key role in the election — like independents, Hispanic voters, and infrequent voters.

That last group was of particular concern for Biden. When he was the nominee, some strategists suggested that higher turnout would hurt Democrats because infrequent voters were less likely to support him.

“There was an overwhelming sentiment among infrequent voters that Biden would not be able to fulfill his responsibilities for a second term, and for the first half of the year, Democrats were publicly in denial about that,” Wasserman said.

But among registered voters who did not vote in 2020, Harris improved by 9 percentage points in New York Times/Siena College polls conducted before and after Biden dropped out, suggesting that she has narrowed Trump’s advantage with that group. That growth suggests she has appeal with voters who aren’t hardcore partisans — and that she might have further opportunities for growth.

Any significant movement among Black and Latino voters toward Trump is also notable and could prove decisive in certain swing states. In 2020, Trump made gains with Latinos not just in Florida and Texas, but also in Pennsylvania. Black voters will play a key role in Georgia, Michigan, and Pennsylvania, and some of them appear to be moving toward Trump.

“It’s lower-propensity Black voters who are open to voting for Trump, and they are not guaranteed to show up. But even so, if Trump wins 15 percent of the Black vote, that would likely be enough to tip Georgia and Michigan and Pennsylvania to the Republican column,” Wasserman said. “That means that Kamala Harris has to make it up somewhere else, and that’s hard.”

To still win after losing those three states, Harris would likely need to sweep the rest of the swing states and pick up a large state that Democrats have struggled in, like North Carolina.

That said, Kondik said that he is skeptical any shift among Black voters would be large, and that polling errors might be overstating the extent to which Black voters are supporting Trump. “I think that’s a mirage,” he said.

If there’s a single issue most likely to determine the election, it’s probably the economy, which is at or near the top of issues that voters prioritize across multiple polls. The economy is also worth watching because it has previously had electoral significance.

A key variable in Sabato’s Crystal Ball’s election forecasting model is economic growth leading up to an election: specifically, second-quarter percent change in gross domestic product (GDP), the total value of goods and services produced in the US.

That change has “proven to be historically electorally important,” Kondik said. Sabato’s didn’t use it in their 2020 model because the pandemic contributed to a big downturn in economic growth that would have suggested Trump would lose in a landslide, which seemed unlikely — and indeed, he ended up losing what was a tight race.

But there’s no reason to believe that this year is similarly exceptional.

“If there’s a big crash, the incumbent party almost always suffers some sort of penalty. This is kind of what doomed John McCain in 2008,” Jain said.

The Federal Reserve started raising interest rates in mid-2022, increasing borrowing costs and dampening consumer confidence in the economy through much of this year. The Fed’s goal was to get high inflation under control; now that inflation has cooled, the Fed is expected to finally cut rates again in September.

A rate cut might not be a complete game-changer for Harris, especially since “a lot of the effect of the economy on the election is already ‘baked in’ at this late date” in that most people have already made up their minds about the Biden administration’s performance on the issue, said John Sides, political science professor at Vanderbilt University.

However, it might give her more ammunition to fight off Republican attacks on Biden’s economic record. Not only would it provide some immediate relief to homeowners and homebuyers by bringing down mortgage interest rates, it would also signal that the Fed is willing to step in to help workers in a tougher job market. A rate cut would ease financial pressure on businesses that kept them from hiring as much as they were during the pandemic.

Trump has blamed Harris and Biden for high inflation and household debt and promised to reinstate “the best economy in the history of our country,” which he falsely claimed was during his first term. (His term saw an annual average of between 2 and 3 percent GDP growth, not counting the pandemic economy of 2020, while yearly GDP growth averaged nearly 5 percent in the 1960s.) That has proved persuasive among the majority of voters who prefer him to Harris on the issue, but Harris has also closed that gap somewhat. Harris has argued that she and Biden inherited an economic mess from Trump and have largely managed to clean it up: inflation is down, growth has remained relatively strong, and the labor market is still on solid footing despite a recent downturn in job growth, all without triggering a recession. However, it’s not clear how effective that argument is among consumers who are still struggling with higher prices and more debt.

“In general, I think a rate cut would be a bit of welcome ‘good news’ for the Harris campaign that might help weaken the Trump campaign’s economic argument,” Sides said.

The amount of dollars spent in presidential elections by each party isn’t necessarily predictive of election outcomes. Piles of cash can’t compensate for poor spending decisions or bad candidates. And there are diminishing returns on ad spending.

But the difference in party spending in major battleground states can reveal something about which party has momentum where, and how competitive they perceive that state to be, Jain said. If one party is being outspent by the other in a particular state, that can indicate one of two things: either they think they already have it in the bag and don’t need to spend more, or they’ve backed off because it doesn’t seem winnable and are focusing their resources elsewhere. As of now, Republicans are being outspent in a few battlegrounds where Trump is not polling as well as Harris (though it’s very close).

Beyond the major battlegrounds, it’s also important to pay attention to spending aimed at expanding the map for either Republicans or Democrats. Any money spent outside Arizona, Nevada, Michigan, Pennsylvania, Wisconsin, North Carolina, Georgia, and Nebraska (which allocates three of its five electoral votes to whichever candidate wins the vote in its three electoral districts) might signal as much. Notably, it seems that both parties are planning to spend fairly heavily in states including Texas and Florida this fall.

That would suggest that Democrats see some path to victory in those traditionally Republican states that isn’t immediately obvious to observers lacking their internal polling, that they feel secure enough in other key states to spend money on long shots, or that they feel they have enough money to force the GOP to “waste” money on states that should be safe for them.

“I’m really curious to see if there’s any heavy television spending in states other than the big seven, plus Nebraska,” Kondik said. “If money is spent in any other place, I’ll be interested in that. So, Republicans go on TV in Minneapolis, St. Paul, or Democrats go on TV this fall in Miami.” Such moves might indicate a party is feeling bullish about expanding the map.