U.S. citizens will vote to select their preferred members of Congress, both for the House of Representatives and for the Senate, as well as state Governors and down-ballot positions such as local representatives and judges.
More Early @NBC Exit Poll results: One In Four Hispanics Say They Cast a Midterm Ballot for the First Time in 2018.
Trump arrived in Fort Wayne, northeast of Indianapolis, where he brought Vice President Mike Pence and hoops coach Bobby Knight on Friday in yet another effort to defeat Sen. "We have added almost 500,000 manufacturing jobs to our economy - jobs that many self-proclaimed experts said would never return", Trump wrote in an op-ed for Fox News. If Republicans are satisfied with legislative paralysis in Washington and happy to see Trump make and implement policy via executive order with the help of a compliant Supreme Court, they'll still get what they want if Democrats take the House.
Democrat Amy McGrath, a former Marine Corps fighter pilot, is running neck-and-neck against incumbent Republican Andy Barr in a House race in Kentucky, a state Trump won by 30 points.
"People are coming out because they care about taking back the House and turning this country around", she said, calling Pelosi an "inspiring leader".
The political realignment, defined by race, gender and education, could re-shape United States politics for a generation.
Just five years ago, the Republican National Committee reported that the GOP's very survival depended upon attracting more minorities and women.
"We energized the Republican Party with that", Trump said in Missouri.
"What it means to be Republican is being rewritten as we speak", Fleischer said.
A nationwide poll released Sunday by NBC News and The Wall Street Journal details the depth of the demographic shifts. He told the AP last month that he won't bear any responsibility should Democrats take over. Democrats expect to flip the 1st District, and the 3rd District with Rep. David Young is a toss-up.
On the other side, Republicans led with voters between the ages of 50 and 64 (52 per cent to 43 per cent), men (50 per cent to 43 per cent) and whites (50 per cent to 44 per cent). Polling suggests the Republican coalition is increasingly older, whiter, more male and less likely to have a college degree.
Democrats hope to elect a record number of women to Congress. "He thinks he's amusing when he says some of these things, but the consequences falling on the wrong ears are not amusing, they're tragic".
In the final sprint to Election Day, Trump has pushed forward with rallies amid news events that would have halted previous leaders - holding a massive event in IL the same day a gunman massacred 11 people in a Pittsburgh synagogue. "But it'll be a start".
Wrapping up the campaign in recent days, Trump repeatedly raised fears about immigrants, issuing harsh warnings about a caravan of Central American migrants that is moving slowly through Mexico towards the USA border. However, Trump walked away with the victory against all odds.
"This is a president who wants this midterm to be a referendum on him, largely because he thinks his own popularity is so great that it will carry Republicans across the finish line", Hudak said. "Democrats produce mobs", Trump said at his final rally in Cape Girardeau, Missouri.
With that in mind, unusually high voter turnout could be a good sign for them.
Tuesday's results will be colored by the dramatically different landscapes in the fight for the House and Senate.
In August, the editorial board of one of the largest newspapers in Pelosi's home state of California, the Sacramento Bee, called on Pelosi to "put her party and her country ahead of her personal ambition and declare that she will not seek the speakership again" after the midterm elections. Forecasting website FiveThirtyEight gave Democrats an 88 per cent chance to win the House, Republicans an 81 per cent chance to keep the Senate.
While keeping the House remained an uphill battle for the GOP, in the closing days of the campaign, Trump and Republicans have tried to sell voters on the possibilities of another two years of GOP control.