Health care, immigration, and President Donald Trump brought voters to the polls on Tuesday with record-level enthusiasm for a midterm election.

“I’ve been looking forward to this day for two years,” says Ben Zylman, a 61-year-old from Kalamazoo, Michigan. "I do believe it's a referendum on Trump and the GOP in general, as they've fallen in lockstep with him."

Zylman, who considers himself an independent, had previously supported GOP Rep. Fred Upton but turned against him after Upton voted last year to repeal the Affordable Care Act.

"Because where I am at in my life, health care is the number one issue," said Zylman, who receives coverage through the ACA.

Republicans tried to run on protecting health care after Democrats made it a centerpiece of their campaign, but Joe Niesen of Madison, Wisconsin, wasn't convinced.

"The Republicans say pre-existing conditions will be covered but we've heard this before in the past," he said. "I do believe the Democrats want universal health care in the long run, and I believe that’s what we should have."

"There's a fire under people to get out and vote," Niesen added.

Heading into the elections, a majority of voters said they saw the congressional races as a referendum on Trump: Thirty-two percent of likely voters said their vote would be a signal of support for the president, and 40 percent said it was a signal of opposition, according to an NBC/WSJ poll conducted last week.

Pamela Aguirre, 77, of in El Paso, Texas, told MSNBC that she supported Rep. Beto O’Rourke for Senate because he “represents everything that Donald Trump isn’t.”

If O’Rourke, a Democrat, wins against incumbent Republican Ted Cruz, it means “we all still have a chance to have a decent country and decent values with decent relationships,” Aguirre said in tears, carrying her oxygen tank to the polls.

Republican voters said the economy and immigration were key issues driving their vote.

Richard Murphy was among the Republican voters who cited the booming economy as a big reason to support the GOP.

“I want to keep things going," said Murphy of Lakewood, California, who voted for Trump in 2016. "My work feels the booming economy. We're hiring more people, all positions, from the bottom to the top.”

Both Republican and Democratic voters have expressed unusually high levels of enthusiasm, according to NBC/WSJ polling, with 70 percent of respondents saying they are highly interested in the midterm contest. A record number of Americans turned out for early voting in Texas and New Mexico.

In the final stretch of the election, Trump tried to rally his base by focusing on a caravan of asylum-seekers trekking hundreds of miles toward the U.S.-Mexico border.

"This whole thing with this caravan is pretty scary," said Jennifer Rager, 55, a Trump supporter from Bozeman, Montana. "I feel like we definitely need protection."

But Democratic voters like Barry Siepelmeyer said Trump's immigration policies were a reason to reject his party.

"The border wall is a bad idea. Walls don’t work — the Berlin Wall didn’t work," Siepelmeyer, a Navy veteran from Red Wing, Minnesota, told MSNBC, calling Democrats "more level-headed."

Amy Hill, a 32-year-old voter in Richmond, Virginia, said she was concerned about immigrants and LGBT Americans losing their rights if Republicans hold onto majorities in Congress.

But like many other Democratic voters, Hill was most concerned that Republicans would undermine health care.

Her three-year-old son has cerebral palsy and receives critical services and medical supplies through Medicaid, which is why she became politically active over the past year and voted for Rep. Donald McEachin, the Democratic incumbent.

"He’s not going to make a vote against my child," said Hill.