– President Donald Trump cast the midterm election as a "big victory" Wednesday, relishing Republican wins in the Senate even as he suffered a major political setback in the House, where he will face an emboldened Democratic majority for the first time in his presidency.

In a combative news conference at the White House, Trump urged Democrats to work with him on bipartisan legislation while threatening a "warlike posture" if they use oversight authority to subpoena his tax returns or cellphone records or to investigate a host of other sensitive matters.

He vowed to respond to Democratic investigations by using the Republican-controlled Senate to launch investigations that benefit him, suggesting that would "probably be very good for me politically because I think I'm better at that game than they are."

"Now is the time for members of both parties to join together, put partisanship aside and keep the economic miracle going strong," Trump said, referencing infrastructure, trade and environmental policy as ripe for bipartisan agreement.

Trump touted his party's Senate gains and taunted Republicans — including Minnesota's Erik Paulsen — who lost their seats, claiming that their decisions to distance themselves from him backfired in suburban districts. Some critics contested that, saying that the president's unpopularity in some areas proved too toxic for several candidates with strong individual brands to overcome.

The president refused to reckon with questions about his own inflammatory rhetoric throughout the race, continuing to blame the media for creating a divisive political climate in a campaign that will be remembered, in part, for a Florida man who mailed pipe bombs to the president's opponents and a gunman who killed 11 worshipers in a Pittsburgh synagogue.

"I'm a great moral leader," Trump said, after he responded to a question about a rise in anti-Semitic hate crimes by pointing to his supposed popularity in Israel. When asked whether his declaration of himself as a "nationalist" in the final weeks of the campaign could have sent a signal of tacit support to white nationalists, Trump lashed out at the reporter asking it, a black woman.

"That's such a racist question," he said.

The president sent mixed signals about whether he should have softened his rhetorical tone, saying he couldn't do so before the midterm election while blaming the media for his divisive, grievance-stoking closing message.

"I would love to see unity and peace and love and any other word you want to use," Trump said toward the end of a long back-and-forth with reporters that featured a number of acrimonious exchanges. "When you're not treated fairly, you really have no choice."

Trump also took issue with questions asked by CNN reporter Jim Acosta, and the White House later suspended Acosta's press pass.

Trump snapped at Acosta after he asked why the president called the Central American migrant caravan "an invasion" and "demonized immigrants." Following a lengthy and tense verbal back-and-forth, a White House intern attempted to take the microphone away from Acosta.

Acosta held onto it and told the woman, "Pardon me, ma'am."

On Wednesday night, White House press secretary Sarah Huckabee Sanders accused Acosta of "placing his hands on a young woman" and said it was on those grounds Acosta's press pass was being suspended "until further notice."

The move to punish Acosta by removing his access to the White House is believed to be unprecedented.

The White House Correspondents Association released a statement Wednesday saying it "strongly objects to the Trump Administration's decision to use U.S. Secret Service security credentials as a tool to punish a reporter with whom it has a difficult relationship. Revoking access to the White House complex is a reaction out of line to the purported offense and is unacceptable."

The WHCA called on the White House to "immediately reverse this weak and misguided action."

Speaking to reporters earlier on Capitol Hill, Senate Majority Leader Mitch McConnell, R-Ky., offered a glimpse of how Republicans will seek to pre-empt investigations by the new House majority, framing them as "harassment" and warning Democrats of overreach as the 2020 presidential cycle starts up, citing Republican attempts to impeach President Bill Clinton in 1998.

"His numbers went up and ours went down and we underperformed in the next election," McConnell said. "So the Democrats in the House will have to decide just how much presidential harassment they think is good strategy. I'm not so sure it will work for them."

While Trump expressed optimism about bipartisan compromise, McConnell acknowledged that split control of Congress makes major legislative progress less likely.

Congressional leaders from both parties say they want to pursue an infrastructure bill and health care legislation, but have provided few details.

Trump told reporters that his tweets congratulating Rep. Nancy Pelosi, the Democratic leader who is hoping to become House speaker again under her party's new majority, were "not sarcastic" and that, despite his constant attacks on her that were a feature of his campaign rallies, he has real respect for her. "I give her a great deal of credit for what she's done and what she accomplished."

Pelosi, meanwhile, celebrated Democratic gains and vowed to focus on "strengthening the institution" of Congress as a check on the executive branch. "We have a responsibility for oversight," she said, promising a judicious approach.

Trump downplayed House losses. He spent most of his time and energy in recent weeks in boosting Senate and gubernatorial candidates, an area where Republicans did relatively well.

"Received so many Congratulations from so many on our Big Victory last night, including from foreign nations (friends) that were waiting me out, and hoping, on Trade Deals," Trump tweeted. "Now we can all get back to work and get things done!"

Trump foreshadowed an aggressive response to Democratic investigations with a vow to use the power of his office to retaliate against Congress, which has a constitutional responsibility to oversee the executive branch. "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," he tweeted. "Two can play that game!"

The Associated Press contributed to this story.