Historic wins for racially diverse and first-time candidates. Questions about former President Donald Trump’s endorsement power. A mixed bag for election deniers. Spring primary season has opened up new questions about the future of the Democratic and Republican parties, while setting up many high-stakes races in November. Consider this: Democrats’ majority in Congress is razor-thin. The Senate is a 50-50 split (with Vice President Kamala Harris’ tie-breaking vote giving them the advantage), and Speaker Nancy Pelosi’s control of the House rests on a tight margin. This year, all 435 House seats and 35 of the 100 Senate seats are on the ballot. Additionally, 36 out of 50 states will elect governors. Four outstanding Senate primaries to watch. Although a number of big nominating contests are behind us, the Republican primaries in Arizona and Missouri on August 2 and the Democratic primary in Wisconsin on August 9 will carry real implications for November. Even later, the September 13 Republican primary in New Hampshire may shape how competitive the battleground state contest will be. 1. In Arizona, Trump-backed Blake Masters is looking to beat out solar energy entrepreneur Jim Lamon and state Attorney General Mark Brnovich for a chance to challenge Democratic Sen. Mark Kelly, who’s running for a full six-year term in November after winning a special election in 2020. Masters is part of a wave of Republicans who have won Trump endorsements after parroting his false claims that the 2020 election was stolen from him and downplaying the actions of the pro-Trump mob that attacked the US Capitol on January 6, 2021. An audio recording of Masters talking with conservative activists this spring captured him floating the debunked conspiracy theory that the attack on the Capitol may actually have been a false-flag operation set up by the FBI. 2. The GOP primary in Missouri will decide whether the state will be in play in November. Trump has faced both tremendous pressure from supporters of Eric Greitens to endorse the disgraced former governor and tremendous pressure to back an alternative, with many Republicans worried about Greitens’ electability in the general election in what should be a solidly Republican state. Greitens faced fresh controversy this spring, when his ex-wife said in a court filing that she has photographs of injuries to their child in 2019 and other documentation of Greitens’ alleged abuse. (Greitens’ attorneys have denied the allegations.) The Republican field here is crowded, including state Attorney General Eric Schmitt and US Rep. Vicky Hartzler, who have drawn support from prominent GOP Sens. Ted Cruz of Texas and Josh Hawley of Missouri, respectively. The more splintered the Republican vote, however, the lower the threshold Greitens would need to win – a big concern for Republicans who would like to see the party quickly coalesce around an alternative to him ahead of the primary. The November contest got a new candidate on Wednesday, when John Wood, a former senior investigator for the House select committee investigating the January 6 attack, launched a campaign as an independent. 3. In Wisconsin, the Democratic Senate primary will shape a fall matchup that represents Democrats’ best shot at unseating a Republican incumbent. Among the Democrats running are Lt. Gov. Mandela Barnes, Milwaukee Bucks executive Alex Lasry, state Treasurer Sarah Godlewski and Outagamie County Executive Tom Nelson. The challenge for whoever prevails? Unseating Republican Sen. Ron Johnson, who broke his term-limit pledge in order to seek a third term in the fall and has a trail of recent controversial comments about Covid-19, vaccines and the insurrection. 4. In New Hampshire, a long list of Republicans are vying for a chance to challenge Democratic Sen. Maggie Hassan after national Republicans’ first choice, Gov. Chris Sununu, passed on the race. His absence has opened up a crowded primary field that includes state Senate President Chuck Morse, former Londonderry Town Manager Kevin Smith and retired Army Brig. Gen. Don Bolduc, who unsuccessfully sought the nomination for the state’s other Senate seat in 2020. Hassan, a former two-term governor, defeated GOP Sen. Kelly Ayotte by just 1,017 votes in 2016, and holding her seat this fall is critical to Democrats’ hopes of maintaining the majority in the Senate. Election denialism has its limits. One emerging lesson for GOP candidates in upcoming primaries is that anchoring your campaign in election lies isn’t always a winning ticket. Take Colorado, for example. Many voters in the state were aghast at the prospect of indicted Mesa County Clerk Tina Peters, who has parroted Trump’s falsehoods about voter fraud, taking over the state’s elections machinery. (She has pleaded not guilty to the 10 counts against her related to voting machine tampering allegations.) On Tuesday, voters in the GOP primary rejected Peters’ bid to take on Democratic Secretary of State Jena Griswold in the fall. Instead, they nominated Pam Anderson, a former county clerk who has defended the integrity of Colorado’s vote-by-mail system. The outcome of two other GOP primaries for statewide office in Colorado – for Senate and governor – underscored a similar theme, with the candidates who had spread election lies or questioned the 2020 presidential results losing. And in Georgia, Republican voters rebuked the election-lie-peddling candidates Trump had recruited to try to unseat GOP officials who rebuffed his efforts to overturn the 2020 results. To be sure, election denialism has prevailed elsewhere. Earlier this month, Republican Jim Marchant, who has said he would not have certified Joe Biden’s victory in Nevada, won his party’s nomination for secretary of state in a key presidential battleground. And last month, Pennsylvania state Sen. Doug Mastriano, a leading voice advancing Trump’s lies about election fraud, won the Republican primary for governor. So while it’s clear Republican voters remain largely supportive of Trump, there are limits to their willingness to entertain his personal grievances. A new Democratic lineup. You don’t have to look further than Pennsylvania Lt. Gov. John Fetterman or former North Carolina Supreme Court Chief Justice Cheri Beasley to see a shift in the Democratic Party taking shape. Fetterman skated passed US Rep. Conor Lamb in the Pennsylvania US Senate Democratic primary, making light work of a polished Marine veteran who had defeated Republicans in tough races for the US House and looked the part of a traditional politician. And the candidacy of Beasley, who could become North Carolina’s first Black senator, eventually forced Jeff Jackson, a state senator who’s a major in the Army National Guard, to end his campaign months before the primary. Across the South, Democrats have nominated Black candidates for top offices, while another – Rep. Val Demings of Florida – is heavily favored to clinch the Democratic Senate nomination in her state in August. Looking under the hood For a better understanding of what primary season is telling us, we turned to CNN Political Director David Chalian. Our conversation, conducted over email and lightly edited for flow and brevity, is below. WHAT MATTERS: What do you make of Trump’s endorsements to this point? His support is obviously coveted in GOP primaries, but it seems like his role as Republican kingmaker is being tested? CHALIAN: I think you have to think about Trump’s endorsement in two different ways. There is the pure endorsement record that shows him doing quite well. But that may be the less meaningful measure because it includes so many endorsements of completely safe candidates in these primaries who are almost guaranteed victory. The more meaningful way to look at Trump’s endorsement record is where he has endorsed in highly competitive GOP primaries. And when it comes to his high-profile Senate endorsements, he’s got a pretty good track record, including JD Vance’s win in Ohio, Ted Budd’s win in North Carolina and Mehmet Oz’s victory in Pennsylvania. He also had a win with Herschel Walker in Georgia, but he was facing minimal competition. However, when Trump has gotten behind a candidate simply to put his continued lies about 2020 being a stolen or fraudulent election (it was not) front and center, he doesn’t tend to fare as well. A prime example of this was his drafting and backing of David Perdue in the Georgia gubernatorial primary. Trump came in for a big defeat there as incumbent Gov. Brian Kemp cruised to victory. It was a similar story in the secretary of state’s race there. I think you can sum up Trump’s mixed record thus far in the primary season this way: Trump is still the biggest political force inside the Republican primary electorate, but he may not be the determinative force. WHAT MATTERS: There’s still a number of big primaries in August. Which races are you going to be watching the closest? CHALIAN: Circle August 16 on your calendar. The Liz Cheney primary against Harriet Hageman is going to be fascinating to watch. Cheney clearly has a very uphill climb inside a conservative Republican primary electorate given how she has separated herself from Trump and her party with her work on defending democracy with the January 6 committee. Trump and his team are heavily invested in this race to defeat Cheney and she could potentially lose her job because she put history, democracy and country above all else. It’s quite a story. WHAT MATTERS: There have also been a number of remarkable developments in Washington between the Supreme Court overturning Roe v. Wade and Tuesday’s explosive testimony from Cassidy Hutchinson. Do you get the sense these will have a meaningful impact on races moving forward? CHALIAN: I think it is way too early to tell exactly how these big news-driving events will impact voting come November. I do believe the economy and inflation is likely to remain the top issue for voters this fall, but abortion rights and accountability for January 6 might certainly motivate some Democratic voters to get to the polls. I think Republicans are clearly trying to make sure to keep every political conversation focused on inflation and the economy above all else, because they believe that’s the strongest argument to make to not only their reliable base voters, but also to the all-important middle.