Primary elections across six states on Tuesday night offered a glimpse into the evolving political landscape, with a premier U.S. Senate race taking shape in Iowa and a rare setback for President Trump’s endorsement record. Democrats also chose a nominee for a U.S. House race in New Jersey that could decide control of the chamber. Much of the focus, however, remained on California, home to Hollywood but a governor's race packing little traditional star power. These contests, spanning California, Iowa, Montana, New Jersey, New Mexico, and South Dakota, provided crucial takeaways for both major parties.Republican Zach Lahn was able to defeat Trump-endorsed Randy Feenstra in Iowa’s GOP primary (AP)Iowa Democrats rallied behind former Paralympian Josh Turek in a marquee Senate primary, setting up a general election clash with Republican Ashley Hinson. Turek, a state representative with a compelling personal biography, defeated State Senator Zach Wahls, who had positioned himself as a more disruptive figure. This victory is closely watched by Democrats, who are increasingly bullish about retaking the Senate majority in November. The outcome could also influence the upcoming Michigan primary on August 4, where Representative Haley Stevens is emerging as the establishment candidate against State Senator Mallory McMorrow and progressive Abdul El-Sayed. New Mexico could make history in governor's race. The stage is set for Deb Haaland to make history this fall after the former U.S. interior secretary secured the Democratic nomination for governor in New Mexico (AP)Both races are crucial for Democrats aiming to protect their Michigan seat and seize pickup opportunities in states like Iowa, with longer-term implications for rebuilding their standing in the Midwest.President Trump’s endorsement streak encountered a significant roadblock in Iowa, despite recent successes in ending the political careers of senators John Cornyn and Bill Cassidy, and Representative Thomas Massie. His backing failed to secure victory for Representative Randy Feenstra in the Republican gubernatorial primary, who narrowly lost to Zach Lahn. This development marks a rare setback for Trump, who 'basks in his ability' to sway Republican votes. The power of Trump's endorsement helped to end the senatorial career of John Cornyn in Texas earlier this month (Getty)Democrats, meanwhile, see this as one of their best opportunities to pick up a governorship this year. They nominated Rob Sand, who ran unopposed and is a proven winner in a Republican-leaning state, having been elected auditor twice. Lahn, a conservative newcomer, built support by championing a total abortion ban and opposing 'liberal ideology' in schools. He also criticized Feenstra for not debating opponents and was endorsed by former U.S. Representative Steve King.California's gubernatorial race has been notably dramatic this year, with approximately 60 candidates vying to succeed term-limited Governor Gavin Newsom. The ballot lacked prominent names like Kamala Harris and Senator Alex Padilla, and former Representative Eric Swalwell withdrew after sexual assault allegations, which he denied. Republican Steve Hilton campaigned with Trump’s endorsement to replace Gavin Newsom in California (Getty)For Californians 'dizzied by the twists,' clarity on choices will take longer. Under the state’s 'top-two' primary system, the two highest vote-getters, regardless of party, advance. Early returns showed Democrats Xavier Becerra, a former congressman and health secretary under President Joe Biden, and billionaire climate activist Tom Steyer, alongside Republican Steve Hilton, who had Trump’s endorsement, leading the field. The results will indicate the level of change sought in a state confronting challenges from affordability to crime, and whether Steyer's $200 million personal investment was effective.In the final days of the campaign, much of the attention focused on Democrats Xavier Becerra, the former congressman and state attorney general who was also health secretary under President Joe Biden, and Tom Steyer, a billionaire known for his climate activism (Getty)If Democrats hope to compete in red-state Senate contests this fall, they may have to abandon their party’s nominees and rally around independents. This strategy is emerging in Montana and South Dakota, where little-known Democrats won primaries but higher-profile independent candidates also qualified for the general election. Similar dynamics are seen in Idaho and Nebraska, where Democratic leaders openly endorse independent Dan Osborne over their party’s nominee. In Montana, independent Seth Bodnar, a former University of Montana president, appears to be the strongest opponent to Republican Kurt Alme, having significantly outraised both Democratic primary candidates and Trump-backed Alme. President Donald Trump has repeatedly threatened any member of his own party who criticizes him with a primary challenge (Getty)In South Dakota, incumbent Republican Mike Rounds will face Democrat Julian Beaudion, but former Democrat-turned-independent Brian Bengs is considered a tougher challenger by some Democrats. This shift reflects the party’s 'toxic brand' in Republican strongholds.A critical U.S. House race is set in New Jersey’s 7th congressional district, where Democrat Rebecca Bennett will challenge incumbent Republican Representative Tom Kean Jr. This district is vital for Republicans defending their narrow congressional majority. The race has drawn scrutiny due to Kean’s extended and unexplained medical absence, having missed over 100 votes since March 5. Bennett, a former Navy pilot, made Kean’s absence a central campaign issue, arguing he wasn’t present to protect funding for a new rail tunnel. This line of attack is expected to intensify. President Trump reiterated his endorsement of Kean, who released a statement confirming his focus on recovery and an anticipated return to 'in-person work within a matter of weeks.'New Mexico is poised for a potentially historic gubernatorial election, as Deb Haaland, the former U.S. Interior Secretary, secured the Democratic nomination. Haaland, who served under President Biden, was the first Native American cabinet secretary and could become the first Native American woman elected governor of any U.S. state. She defeated District Attorney Sam Bregman in the primary, campaigning on her ancestral roots, cost-cutting, and her governing experience. Haaland will now face Republican Greggory Hull in the general election.