He claimed Monday that Democrats wanted to make America "a giant sanctuary city for drug dealers, predators, and bloodthirsty MS-13 killers".
There are key races right off the bat with the Georgia governor's race, the Indiana Senate race and House races in Virginia and Kentucky, in particular.
Billionaire Michael Bloomberg, who advocates gun control, poured millions into House races for Democrats, offsetting the big-dollar spending to save Republicans by the Congressional Leadership Fund, which is aligned with House Speaker Paul Ryan.
There are several other competitive gubernatorial races closing this hour, too.
Among white college-educated women, Democrats enjoy a 28-point advantage: 61 per cent to 33 per cent.
What is the Trump-o-Meter?
Stirring fear of foreigners and trumpeting American nationalism worked for Trump in his 2016 election victory against the Democrats' establishment candidate Hillary Clinton.
To help explain the complex array of election results, Stuff is using a kind of Trump-o-Meter, to condense the numbers into one of five Trump emotions: Unfair!; Sad!; OK; Terrific!; or YUGE!
The Democrats also had history on their side: 2002 was the only midterm election in the past three decades when the party holding the White House gained Senate seats.
While political pundits may ultimately analyze Tuesday's results as a test of Trump, many Americans will undoubtedly base their vote on factors other than their feelings about the president: economic indicators, health care, tax reform, immigration or just their overall comfort level with the direction the country is headed. Democratic Senate incumbents were up for re-election, for example, in North Dakota, Indiana, and Missouri - states Trump carried by nearly 25 percentage points on average two years ago.
So another reason we need not be concerned about surprises in today's vote is that it was the idiosyncrasies of the United States presidential election system that turned a marginal error into a surprise president in 2016, and this system does not apply to the midterms. And why do they matter?
Georgia offers two key races in the Atlanta suburbs - one of which is the 6th District, which was the site of a hotly contested special election previous year that Republicans held, but polls show the race is even tighter this time around.
What does it mean for Trump?
The Republican Party is expected to retain its majority in the Senate.
More good news for the GOP: "Seventy-seven percent (77%) of Republicans say they always vote in midterm elections, as do 71% of Democrats and 63% of voters not affiliated with either major political party".
A Democratic blowout in Tuesday's midterms would be debilitating for President Donald Trump and Americans, according to former White House communications director Anthony Scaramucci.
What are the chances of that happening? But more significantly, polls suggest that Trump will lose control of the House of Representatives in today's vote. US House of Representatives - similar to India's Lok Sabha - has 435 seats, of which the Republicans in the current Congress has 235 seats and the Democrats have 193. Now Democrats are hoping to return the favor by flipping seats in the suburbs and some GOP-dominated rural areas.
Either way, election watchers who want to see which party wins control of Congress probably won't be going to bed early tonight.
An 86% chance is not a sure thing, but it's a strong indicator of the most likely outcome. The Republicans are expected to increase their tally in the 100-Senate seat where they already have a very thin majority. Democrats hold 47 seats and independents two. "For the past two years, we've watched this administration attack and undermine our democratic institutions and values".
Ballots in the U.S. can be cast in person or online, but for both you must be registered first.
With the first polls not slated to close until 6 P.M. eastern, polling was the only indicators both parties had on Tuesday of their prospects.
The first polls opened at 5am (10am GMT) local time in Vermont.