Image copyright AFP/Getty Image caption Voters will cast their ballots across the country on Tuesday What happens on election day?
Compounding that problem would be the lack of a clear leader as the Democrats looked ahead to the 2020 election. Candidates and their supporters are using the downtime to phone bank voters who still haven't voted and walk as many neighborhoods as possible.
The US midterms will be a referendum on Donald Trump's presidency.
The crowd thundered in approval.
And the sudden emergence of a huge caravan of migrants heading toward the United States border just before the election has also fired up both bases, but especially conservatives who are concerned about border security. Republicans now hold 51 against the Democrats' 49 (with two independents).
During his final campaign rallies in Ohio, Indiana and Missouri, Mr Trump returned to his key campaign issues, insisting that Democrats would damage the economy and allow more illegal immigration. That was by design.
When he spoke to Four Corners in September, Trump's former top political adviser Steve Bannon warned there would be "civil war" in the party.
"The Drive-By Media is so invested with two things: Love and adoration for the Democrat Party and sheer dislike for us".
"You want to see Georgia prosperity end?"
"It's a sign of their weakness. They may not be flawless, but who is?" Mr. rose was inspired by the fresh approach of Mr. Trump's vision for the country but feels let down.
She also backs Trump and said Republicans are moving in the right direction on health care. "We have to give America two choices here".
And polls running up election day suggest the Democrats have a huge chance of winning the House. 3% of likely voters said they would choose another candidate while 6% were undecided. It all depends on how accurately they have predicted voter turnout.
If they do win control of the House, Democrats will try to harden USA policy toward Saudi Arabia, Russia and North Korea, while maintaining the status quo on hot-button areas like China and Iran. "Candidates have been remarkably disciplined about not being distracted by shiny objects".
Fact-checker sites state that Trump got 41 percent of the female vote in that election, though he did get 52 percent of votes from white women.
"It's all fragile. Everything I told you about, it can be undone and changed by the Democrats if they get in", Trump told supporters Monday during a telephone "town hall" organized by his re-election campaign.
Nevertheless, electoral projections support the restrained approach.
Polls show Democrats have a strong chance of retaking the House on Tuesday, but they shouldn't open the champagne yet-even if they do win, it could take weeks to be confirmed, according to a New York Times analysis. Democrats are expected to fall short of the two seats they need to reach the majority in the Senate. "Trump has done a good job at keeping Republicans angry".
When a HuffPost/YouGov poll asked 1,000 USA adults to pick their top two election issues, 30 percent of voters chose health care.
With Trump's every provocative word seemingly splayed across cable news daily, the strategy has often led to a jarring juxtaposition outside of Washington.
For nearly two years, Trump's rule-breaking, sometimes chaotic administration has enjoyed a largely free hand from the twin Republican-controlled chambers, but the midterms could finally see his wings clipped.
The small minority of ads that do attack Trump includes those by "Need to Impeach", an advocacy group founded by California billionaire Tom Steyer.
Trump campaigned with Georgia Secretary of State Brian Kemp, who is in a tight race with Democrat Stacey Abrams for the governor's office.
But in Indiana, Obama said Republicans were taking credit for the economic renewal that started under his presidency. "When you vote, Illinois, you can choose hope over fear", he said.