As Democrats prepare to take control of the House on Jan. 2, President Trump has a message for his political opponents who are feeling emboldened by their soon-to-be acquired subpoena power: If Dems try to use their subpoena power to launch Congressional investigations into his tax returns or Russia ties, the Trump Administration won't cooperate with them on matters of policy.

During a raucous Wednesday press conference (the same press conference where he berated two CNN reporters), Trump again threatened Democrats with partisan gridlock if they try to probe him or his administration. Trump said that, since before he announced he would run, Democrats have been bombarding him with "investigation fatigue" - as he phrased it. He then threatened to adopt a "war posture" if Democrats try and come after his tax returns, or launch another investigation into his Russian ties.

He then made clear that, if they pursue an investigation, Republicans in the Senate would launch an investigation of their own into leaks of classified information by Democrats, including former FBI Director James Comey.

"They can play that game but we can play it better," Trump promised.

He also suggested that if Democrats want to work with the administration on policy priorities like infrastructure, they shwould drop any plans for further investigations. Otherwise, Trump said, they should expect two years of partisan gridlock.

"They want to do things. I keep hearing about investigations - fatigue. From almost the time I announced I was going to run, they've been giving us this investigation fatigue. We have a thing called the United States Senate - and a lot of questionable things were done. Leaks of classified information. All you're going to do is end up with a back-and-forth-and-back-and-forth and all of a sudden two years will go by and you won't have done a thing."

In a brief respite from his typically antagonistic tone toward Democrats, Trump reversed course minutes later and praised Democratic leader Nancy Pelosi over her calls for bipartisanship Tuesday night, adding that Pelosi "loves this country." He even sarcastically offered to push Republicans to vote for her as speaker if progressive Dems make good on their campaign threats not to vote for her.

"We actually have a great relationship," Trump said of Pelosi. "I give her a great deal of credit for what she’s done and what she’s accomplished." [...] Pelosi "loves this country, and she’s a very smart woman," Trump said, adding that he had "a very warm conversation" with her on Tuesday.

Asked how he would respond to Democratic demands that he release his tax returns, Trump repeated an oft-used line about waiting for audits to be completed.

Trump warns Democrats against using their new power to investigate him after Republicans increased their seats in the Senate #Midterms2018 https://t.co/bxjqu8xnA0 pic.twitter.com/jJpScMTJwy — TRT World Now (@TRTWorldNow) November 7, 2018

In a press briefing given shortly after the president's, Pelosi sounded undeterred, clearly stating that Democrats have investigation plans ready.

"We have a constitutional responsibility to have oversight," Pelosi said. "This doesn’t mean we go looking for a fight." She added that she hopes the administration will respond to requests for information voluntarily, but regarding a possible inquiry into the policy of separating families at the border, she said: "If that requires a subpoena, so be it."

Trump used a similarly defiant tone in a tweet posted earlier on Wednesday, where he warned Democrats against "wasting Taxpayer Money" on House investigations.

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! — Donald J. Trump (@realDonaldTrump) November 7, 2018

But given Democrats' eagerness to take full advantage of their subpoena power, it appears the era of bipartisan "love" that Trump had promised after Tuesday night's election might be over before it even began.