The balance of power in the Senate is on a knife’s edge, and control of the chamber might come down to whether Democrats can actually hold on to two states they see as key to their future: Arizona and Nevada.

Both of these fast-growing and increasingly diverse states in the Southwest still have large numbers of uncounted early votes to tally up today and into the end of the week, and both will be crucial to Democratic success in 2024.

The two states were always expected to be close, but a combination of election misinformation, election-denying Republican candidates, voting lawsuits, and large amounts of mail-in votes will complicate the picture of an eventual winner.

In Arizona, Democrats are leading in all four of the top statewide races, buoyed by strong election day and early-arriving early votes. Ticket-splitting seems high, with Republican senatorial candidate Blake Masters receiving fewer votes than the Republican gubernatorial candidate Kari Lake. Democratic Sen. Mark Kelly, meanwhile, is performing better than the Democratic gubernatorial candidate Katie Hobbs — though both hold leads.

In Nevada, strong election-day vote totals have Republicans leading in most of the statewide contests, but large numbers of outstanding mail-in votes, especially from the state’s largest municipality, Clark County, home to Las Vegas, will likely close up that gap. Now the question is how close it will become. Currently Republican Senate nominee Adam Laxalt holds a 2 percentage point lead over Democratic Sen. Catherine Cortez Masto, widely seen as the most vulnerable Democratic incumbent, while the Republican candidate for governor, Joe Lombardo, is leading the incumbent Democrat Steve Sisolak by a wider 5-percent margin. In other words, ticket splitting also seems probable here; Laxalt is underperforming compared to Lombardo.

With Senate results still inconclusive in Georgia, and the possibility that the race heads to a run-off election next month, Democratic hopes of securing the Senate this week could depend on both southwestern Senate incumbents holding these seats.

Buckle up for a messy week of waiting for those answers.

Arizona’s tight statewide races

Arizona, a breeding ground for election conspiracies, always seemed likely to cause some mayhem. In the closing days of their campaign, election denying candidates Kari Lake and Blake Masters were preparing their base for the possibility of voter fraud and sowed doubt in the election results. Poll watchers, some armed, patrolled ballot drop-off sites. Elections workers were pummeled with threats.

On Election Day, printing machine problems at 60 polling places in Maricopa County, the most populated county in the state anchored by Phoenix, fueled conspiracy theories (including one pushed by former President Donald Trump) that Republican votes were being suppressed. Those printing malfunctions didn’t affect the integrity of the ballots submitted; the printers weren’t producing ballots with dark enough marks to be counted by machine, and those ballots were set aside to be counted separately on Wednesday. Nevertheless, that conspiracy was pushed by Lake, Masters, and conservative activists like Steve Bannon.

Still, Lake, Masters, and the Republican National Committee saw the setback as an opportunity to try to extend voting times in Maricopa County, filing a lawsuit to keep polls in the county open until 10 pm (they would usually close at 7 pm) and claiming that voters were dissuaded from voting because of those printer problems and confusing instructions from poll workers. A county judge rejected the motion a few minutes before polls closed.

By the end of the night, Maricopa County had posted two updates to its vote count, giving Mark Kelly a 6-point lead over Masters, and Katie Hobbs a one-point lead over Kari Lake. Still even more surprising were down-ballot races, where Democratic candidates were leading by a little over a point in the race for attorney general, and by a large 6-point lead in the secretary of state contest, where 2020 election conspiracy theorist Mark Finchem was losing to Adrian Fontes, the Maricopa County recorder who oversaw the county’s count of votes in the 2020 presidential election.

Election conspiracies have a long history in the state: In 2020 Fontes was at the center of the firestorm surrounding Maricopa’s counting of ballots, and an eventual audit of votes cast in the state. Though he lost reelection that year, he presided over Maricopa’s count when armed protesters surrounded the election office in which ballots were being tallied and Trump’s in-person Election Day lead in the state began to vanish. In 2018, logistical problems in the primary election and unfounded election conspiracies, some pushed by Trump, in the general election also surrounded Fontes. As hundreds of thousands of mail-in ballots were being counted in the Senate contest between Martha McSally and Kyrsten Sinema, Sinema’s lead only grew, prompting Trump to claim “electoral corruption” and call for a new election.

As various explainers reminded people at the time, Arizona is always slow to report totals because of the overwhelming number of people who vote by mail in statewide elections — that often means that strong initial showings are bound to change as more ballots are processed. Now elections in Maricopa County are being run by Fontes’s successor, the Republican Stephen Richer, and he’s already apologized for the printing malfunctions.

With about two-thirds of the vote left to be counted in Arizona and in Maricopa County, an update is expected to come in the evening today. Because the votes released so far are of ballots cast by last Friday, plenty of Republican-leaning votes have yet to be counted — and margins will tighten.

Nevada’s tight statewide races

Nevada presents another daunting test of patience. In-person turnout in Clark County was much lower than expected all of Tuesday, and long lines by the time polls closed at 7 pm meant that in-person votes would take much longer to be counted. Nevada state law mandates that no official results be posted until the last person in line at a polling place has cast their ballot, so results didn’t creep in from the state until past midnight.

By that point, a lawsuit from Nevada Democrats and Catherine Cortez Masto’s campaign to try to keep polling places open had failed, and the number of ballots outstanding was coming into view. Early Wednesday morning, there were nearly 100,000 mail votes in Clark County, another 2,000 ballots that must be cured (corrected for mistakes) in Clark, and the possibility of even more late-arriving ballots. (The state allows for ballots to be postmarked by Tuesday and arrive until the end of Friday.)

Because of Clark County’s Democratic lean, that might be enough to pull Cortez Masto over the finish line. Ticket splitting and candidate quality issues seem to have ensured that Joe Lombardo, the more conventional GOP nominee for governor, performed better than the election-denying, far-right senate candidate, Adam Laxalt. The governor’s race is not as tight as the Senate race: Lombardo leads Sisolak by 5 points, while Laxalt is only 2 points ahead of Cortez Masto. Elections in the state frequently are decided by a 1 to 2 point margin. Cortez Masto won by 2 points in 2016, while a close race in 2012 was decided by about 1 percent.

Limited staffing and the sheer amount of votes that remain to be counted mean that vote counting in Nevada may take days, the Nevada Independent reported. The vote difference in statewide races is expected to narrow as that happens. That won’t be because of voter fraud, but because of the strong and vocal presence of election denying candidates in the Senate and secretary of state races, the risk of a premature declaration of victory is not out of the question.

Though we don’t have full figures for how specific demographic groups voted, Latino voters and suburban voters stand to leave a significant impact on these statewide contests. Election deniers are close to losing in both states, and two Latino candidates, Cortez Masto and Fontes, could make some history. Cortez Masto would still hold the title of the first and only Latina senator, and Fontes being the first Latino to win a prominent statewide office in nearly 50 years would also show that Latino candidates have a path to statewide victory in Arizona.

Both Arizona and Nevada have Senate seats up for reelection in 2024, and as I’ve written, both states are integral to Democratic success in the future, and to the hope that they can build a Sun Belt “blue wall” in future presidential races.