Honeymoon over?

President Donald Trump faces a barrage of investigations targeting everything from his taxes to his Russian business ties after Democrats captured the House of Representatives in Tuesday's elections.

With the House in their control beginning in January, Democrats will replace Republicans at the head of every committee, giving them the power to set hearing agendas, call witnesses and issue subpoenas to top officials of Trump's administration.

Hours after the election results became clear, Trump tweeted a warning Wednesday morning that he was ready to fight fire with fire.

"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!" he said.

Losing his Republican majority in the House removes much of the insulation that has been crucial to Trump's political success in his first two years.

Now Democrats could lay bare alleged conflicts of interest, misuse of funds, and abuse of power by the president and his cabinet.

Investigations could gridlock a White House already besieged by the Russia collusion investigation by Special Counsel Robert Mueller, heavily bogging down the administration's agenda and foiling Trump's message.

And, indeed, after Trump fired Attorney General Jeff Sessions Wednesday, putting the Mueller probe in jeopardy, Democratic Congressman Jerry Nadler warned that he intended to lead a House Judiciary Committee examination.

According to some estimates, two dozen probes could be opened quickly.

Democrats have already piled up scores of subpoenas of documents and witnesses which Republicans have repeatedly rejected over the past two years.

"We are going to have to ruthlessly prioritize because there is so much that has gone wrong," Democrat Adam Schiff, who is expected to become chairman of the House Intelligence Committee, said ahead of the election.

The Intelligence Committee will press ahead with the Russia election meddling investigation, and Trump's business relations with Russians.

The Judiciary Committee, expected to be headed by current senior Democrat Jerry Nadler, has its eyes on business conflicts of Trump's family. Nadler could also launch a probe into the Russia meddling issue, preparing the ground for a possible impeachment motion against Trump.

The House Ways and Means Committee is expected to subpoena Trump's long-hidden tax returns amid suspicions the billionaire has paid minimal amounts for years and possibly expose hidden foreign ties.

Asked about it on Monday, Trump replied stiffly: "I don't care. They can do whatever they want and I can do whatever I want."