Republicans’ dreams of a red wave that would wash Democrats in Congress and state capitals out to sea proved to be overly optimistic as Democrats held on to key gubernatorial and Senate seats enough so that control of Congress remained up in the air Wednesday morning.

Democrats held on to a crucial Senate seat in New Hampshire, where incumbent Maggie Hassan defeated Republican Don Bolduc, a retired Army general, and managed to flip Pennsylvania’s Senate seat with a victory by John Fetterman. Republicans held Senate seats in Ohio and North Carolina, but it was still too early to call Senate seats in Wisconsin, Nevada, Georgia and Arizona that could determine the majority.

Democrats also were successful in governors’ races, winning in Wisconsin, Michigan and Pennsylvania, but Republicans held on to governors’ mansions in Florida, Texas and Georgia. In the House, meanwhile, Democrats kept seats in districts from Virginia to Kansas to Rhode Island, while many districts in states like New York and California had not been called.

A shock described as nothing less than seismic followed from the state of Florida. Governor DeSantis and Senator Rubio handily won Miami-Dade county, which, just six years ago, Hillary Clinton won by 30 points. Mr. DeSantis himself lost the county by 20 points when he first ran for governor in 2018. A similar pattern followed in Puerto Rican-heavy Osceola County in Central Florida. 

Florida’s 29 electoral votes, the pundits proclaimed after the night’s results, will be out of reach for the Democrats for the foreseeable future if the GOP capture holds. Florida is no longer a swing state, they said. It’s a red state if the Democrats can’t win Miami-Dade to offset GOP strength elsewhere in Florida.

In celebrating his victory, the Florida governor leaned into the culture wars that have served him so well so far.

“We have embraced freedom. We have maintained law and order. We have protected the rights of parents. We have respected our taxpayers, and we reject woke ideology,” Mr. DeSantis said at a rally in Tampa. “We will never ever surrender to the woke mob. Florida is where woke goes to die!”

The Democrats fared better in other races being eyed as potential bellwethers for the night. Republicans came close to unseating two incumbent Democrats in deep-blue northern Virginia, Abigail Spanberger and Jennifer Wexton, but ultimately failed, and incumbent Senator Bennet in Colorado managed to fend off a challenge from one of the GOP’s least Trump-aligned candidates, Joe O’Dea.

Democrats also prevailed in New York’s hard-fought race for governor. The incumbent, Kathy Hochul, declared victory over her Republican opponent, Congressman Lee Zeldin, shortly before midnight.

“Tonight you made your voices heard loud and clear. And, and you made me the first woman ever elected to be the governor of the state of New York. But I’m not here to make history, I’m here to make a difference,” Hochul told supporters late Tuesday night.

Candidates backed by President Trump did not perform as well as the GOP might have hoped. Along with the three key battleground states, gubernatorial elections in Maryland, Massachusetts, Illinois, and Colorado all went to the Democrats, though voters in Arkansas did opt for Trump alumnus Sarah Huckabee Sanders and Georgia’s governor, Brian Kemp, easily bested Stacey Abrams to keep his seat. 

Exit polls suggested that the electorate is not in a good state, but neither party seemed to be capitalizing on it to the extent they hoped. Early exit polls released by CNN illustrated the depth of anger. One brutal question asked about the way things are going in the country. Nearly three-fourths of respondents said they were either “dissatisfied” or “angry” about the state of the nation. Only 25 percent said they were either “enthusiastic” or “satisfied.”

Turnout hit record levels in several states, but reports of irregularities or other problems were relatively few. Mr. Trump, always eager to return to his favorite grievances, wasted no time before complaining after some hiccups involving printer settings stirred up his base at Maricopa county, Arizona. In a social media post, he called on Americans to “protest, protest, protest” what he described as a “voter integrity DISASTER” in Arizona.

In an interview that aired on NewsNation Tuesday, the former president and 2024 frontrunner for the GOP sought to make sure that the outcome of the day’s voting is a win-win for him regardless of which party, if any, can boast of a decisive victory. “I think if they win, I should get all the credit – and if they lose, I should not be blamed at all,” Mr. Trump said of his fellow Republicans.

Mr. Trump was not alone in his suspicion about the integrity of the vote. Before the polls had even closed in Georgia, Democratic activists were taking to the airwaves to denounce the night’s results. In a mid-afternoon appearance on MSNBC, contributor Jason Johnson was already calling into question the legitimacy of the vote. 

“The level of voter suppression is beyond anything that we saw in 2018,” Mr. Johnson said. “We can’t say that whatever happens tonight is a fair and equitable election, because there have been too many laws passed by election deniers to keep people from being able to express themselves.”