The results will probably set in motion investigations into the war in Iran, the running of the FBI and, of course, Donald Trump's family business dealings. Think Bill Clinton's Whitewater scandal and Trump's first impeachment rolled into one, with Iran-Contra thrown in for extra froth.
How will these seismic political shifts impact Europe? From energy prices to the war in Ukraine, the continent has a lot riding on what happens in Washington. Here are five things to watch out for.
Europe risks bearing the brunt of Trump's frustration
Some seasoned observers think this is not only possible but highly likely. "We need to brace ourselves for not more harmonious transatlantic relations but more acrimony and even more Trump demands on Europe," warned Wolfgang Ischinger, the veteran German diplomat and longtime chair of the Munich Security Conference.
Democrats will have more opportunities to challenge Trump through appropriations procedures and by being more aggressive in oversight hearings and probes. They will also likely start attaching stricter conditions to legislation the White House wants.
But a U.S. president has considerable constitutional discretion over foreign policy, diplomacy and national security — as well as trade policy — and Trump has unabashedly grabbed more by using edicts and developing novel, contentious legal maneuvers to bypass Congress.
"[Trump] leads military force. He has control over tariffs and trade deals. He has the bully pulpit. Even if Democrats take both houses, he can veto bills," Phil Gordon, former national security adviser to ex-Vice President Kamala Harris, told Brussels Playbook.
Expect more confrontation. Trump will likely want to show he's still the boss and a master of the universe — and he has more chance to do that on the international stage. Europe has long been in his crosshairs and those of MAGA stalwarts, who shed crocodile tears for the continent, saying they want to save Europe from itself.
They now only have two years to do so. Pedal to the metal!
Breathing space for Ukraine
Most leading Democrats have consistently backed sending aid to Ukraine, framing it as a defense of global democracy and international law — as well as being in America's national security interests.
The Democrats can begin to create the circumstances to assist Ukraine. But don't "expect instant salvation for Zelenskyy," said Bronwen Maddox, director of the U.K.'s Chatham House think tank. "Because even if the Democrats decide to start sending Kyiv more things, including money, that really will take months to unfold and even possibly years," she said
Ukraine needs immediate assistance, especially Patriot missiles for its air defenses, to get through this winter under Russia's continuing bombardment.
A Trumpian peace deal
Trump has framed himself as the president of peace and loudly claims to have ended eight international conflicts. He's said Ukraine should have been the easiest peace deal to conclude and has increasingly blamed the country's president, Volodymyr Zelenskyy, for failing to reach an agreement.
Former U.S. diplomat Kurt Volker reckons Trump will ignore protests from Kyiv and European allies and "start lifting sanctions and doing business deals with Russia."
He said: "I can very well see him doing that unilaterally and directing the U.S. Treasury to refrain from implementing sanctions and trying to get more deals on energy with Russia. He's been talking with Putin about getting the U.S. majors back into Russia."
But when it comes to NATO and following through on threats to reduce U.S. deployments on the continent, Volker expects Trump will be more bark than bite. "With NATO, I think not much is gonna change much when it comes to pulling out of NATO or force posture reduction. Trump is really alone on this in the U.S. — he doesn't have support from Democrats, Republicans, Congress, or the media."
A fall in energy prices
Will energy prices plummet? Don't bet on it. On Monday, oil prices fell at their fastest pace since August — though Brent crude, a key international benchmark, still traded at $108 a barrel.
Unless Trump strikes a peace deal with Tehran to reopen the Strait of Hormuz, the prolonged energy shock that's spiking power costs in Europe and adding to the cost-of-living crisis will continue — skewing European politics. On air travel and the airline industry, Ryanair CEO Michael O'Leary warned that without a deal, the industry will be "facing a real crisis by next March or April."
Trump doesn't have good choices on Iran: relaunch military operations in the hope the Iranians will back down or the theocratic regime collapses; back down himself; or walk away and say others — i.e. the Europeans or Asians — need to solve the problem.
Resuming military operations and spiking energy prices even more will be highly unpopular in the U.S., but the electoral damage has already been done.
Just chaos — with not much time for anywhere else
There's also a chance that the U.S. will become so distracted and consumed by the political warfare in Washington that neither Trump nor the Democrats have much time for anything — including foreign policy.
Former Vice President Kamala Harris warned on a podcast last month that the Democrats shouldn't try to impeach Trump again, dismissing it as "not a good idea."
Rahm Emanuel, the former mayor of Chicago, has urged fellow Democrats to avoid a "food fight" and to focus legislative priorities on affordability, raising the federal minimum wage and developing new ethics rules for all three branches of government.
Despite the pleas, Washington has seldom avoided vicious food fights.
And the political bloodletting is likely to wash up everywhere, with some of the biggest fights inside each party, forecasts POLITICO's John F. Harris. "Both major parties face acute choices about how to present themselves to voters in the coming post-Trump era of politics," Harris argued.
