The U.S. Capitol is seen in Washington D.C. Nov. 6, 2018. The U.S. Republican Party on Tuesday managed to maintain a Senate majority in the midterm elections, while the Democrats wrestled the House majority from the Republicans, according to projections of multiple news outlets. (Xinhua/Liu Jie)

After midterm elections set up a divided Congress on Tuesday, President Donald Trump claimed the results a "tremendous success" for his Republican Party, while a senior Democratic congresswoman envisioned "a new day in America" onward.

The nationwide races, in which Americans chose their representatives in both the upper and lower chambers of the legislature as well as state governors, saw the Republicans consolidate majority in the Senate and the Democrats retake control of the House.

The midterm election results will have profound impact on U.S. politics for the next two years.

"Tremendous success tonight. Thank you to all!" Trump tweeted on Election Day night, as votes were still being counted. The president continued to refer to the results as "big victory" and "very big win" in several follow-up tweets.

That the GOP will fend off Democrats' bid for Senate majority in this election cycle had been well predicted, and the fact that they have extended their on-seat edge in that chamber may imply even more legislative impasse in the years ahead.

The Democrats, however, also had reason to celebrate, as they already crossed the 218-seat line to clinch House majority for the first time in eight years. Although ballots counting is still in the process, the Democrats are projected to gain a net win of more than 30 seats in the House, well beyond the 23 threshold needed to flip Republican control.

Nancy Pelosi, the House minority leader who soon may be speaker, said when addressing a cheerful crowd that a House led by Democrats will herald "a new day in America."

"We have all had enough of division ... The American people want peace. They want results," the congresswoman said, adding that the new majority will defend Medicaid and Medicare - signature programs under former President Barack Obama only to be repealed by the Trump administration.

"Voters delivered a resounding verdict against congressional Republicans' attacks on Medicare and Medicaid and the Affordable Care Act and people with pre-existing conditions in districts everywhere in America," she said Wednesday when addressing reporters.

Trump struck a much hostile tone concerning some of the thorniest issues that divided U.S. politics, ranging from Democrats' request that Trump reveal his tax returns to the investigation into possible collusion between the Trump presidential campaign and Russia. He lashed out at any Democratic attempt to use the subpoena power they newly retained in the House.

"If the Democrats think they are going to waste Taxpayer Money investigating us at the House level, then we will likewise be forced to consider investigating them for all of the leaks of Classified Information, and much else, at the Senate level. Two can play that game!" Trump wrote in a Wednesday morning tweet.

Referring to possible stepped-up investigations into his alleged collusion with Russia and obstruction of justice, Trump told reporters at the White House hours later: "If they (the Democrats) do that, then it's just ... a warlike posture."

At the same press conference Trump also said he is willing to work across the aisle with the Democrats in the House. "Hopefully, we can all work together next year to continue delivering for the American people, including on economic growth, infrastructure, trade, lowering the cost of prescription drugs."