WASHINGTON — President Trump has been warring with Jeff Sessions ever since the attorney general recused himself from the FBI investigation into Russian election meddling, which has led to the mounting legal problems for Trump and his associates as special counsel Robert S. Mueller III investigates potential collusion.

Now, after last week’s guilty plea from Trump’s onetime personal lawyer Michael Cohen, the tax fraud conviction of former Trump campaign manager Paul Manafort and news that the Trump Organization’s longtime chief financial officer may be cooperating with prosecutors, the president is stepping up his attacks against Sessions and appears to be laying the groundwork to fire the nation’s top law enforcement official.

Congressional Republicans, once solidified in their support for Sessions and strongly against his ouster, now look to be wavering — and that apparently has emboldened Trump to suggest he may soon take action.

In tweets Saturday morning, Trump again sought to distance himself from the Cohen case and implications that he did anything wrong, and he wrote: “Jeff Sessions said he wouldn’t allow politics to influence him only because he doesn’t understand what is happening underneath his command position. Highly conflicted Bob Mueller and his gang of 17 Angry Dems are having a field day as real corruption goes untouched. No Collusion!”

Trump then tweeted remarks made by Sen. Lindsey Graham (R-S.C.) on Friday when the senator was asked by Fox News about the acrimonious relations between Trump and Sessions: “Every President deserves an Attorney General they have confidence in. I believe every President has a right to their Cabinet, these are not lifetime appointments. You serve at the pleasure of the President.”

Moments later, Trump brought up his long-running complaint that Sessions and the FBI had not done a proper job of investigating the controversy over Hillary Clinton’s use of private emails while she was secretary of State.

Referring to a Fox report on the email scandal, Trump tweeted: “Big story out that the FBI ignored tens of thousands of Crooked Hillary Emails, many of which are REALLY BAD. Also gave false election info. I feel sure that we will soon be getting to the bottom of all of this corruption. At some point I may have to get involved!”

Whether his comment that he may get personally involved was referring to Sessions wasn’t clear, but the latest tweets reflect the president’s swelling agitation at the continuing and widening probe by Mueller. And in citing Graham’s remarks, Trump may have concluded that he has enough political space to remove Sessions.

Trump has made clear he wants to shut down the special counsel investigation, or at least refocus it on his political enemies, and Sessions is his biggest obstacle right now. But such a move would have major legal and political repercussions, raising the prospect to obstruction of justice and further jeopardizing several vulnerable Republicans in the upcoming midterm elections.

Another high-ranking GOP senator, Charles E. Grassley of Iowa, who chairs the chamber’s Judiciary Committee, also has signaled openness to replacing the attorney general. And conservative activists like Rep. Dana Rohrabacher, the embattled Orange County congressman, are joining radio and TV pundits on the right goading Trump on, accusing Sessions of disloyalty for refusing to shut down the Russia investigation.

Even so, a number of other Republican lawmakers, including the Senate GOP whip, John Cornyn of Texas, in recent days renewed their support for Sessions and essentially called on the president to back off.

Sen. Ben Sasse (R-Neb.), who sits on the Judiciary Committee, warned he will not vote to confirm the attorney general’s replacement should Sessions be fired for refusing “to act as a partisan hack.” The conservative group Republicans for the Rule of Law has been running ads mocking Trump’s oft-stated claim that Mueller’s probe is a “witch hunt,” and warning the president not to interfere with the special counsel’s work.

Democrats, meanwhile, are demanding Congress pass legislation to shield the special counsel investigation from being disbanded by Trump or his administration, even as Republican leaders balk on advancing it.

“While I have opposed many of the actions taken by Attorney General Sessions, it would be unacceptable for the president to fire him now in order to install someone willing to subvert the Mueller investigation,” Sen. Dianne Feinstein (D-Calif.), the top Democrat on the Judiciary Committee, said in a statement.

The Republicans have argued throughout the probe that they are confident Trump would not try to interfere with it, and thus, they said, legislation protecting Mueller was unnecessary. Now, the president has complicated matters for them.

For Graham, a senior senator who sits on the Judiciary Committee, it was only a year ago that he had warned Trump against firing Sessions, saying that there would be “holy hell to pay” if Trump took such action.

But in reversing course this week, Graham said that while Sessions is a “fine man” and “has been a good attorney general,” his working relationship with Trump was neither sustainable nor profitable for the nation.

The president is “entitled to an attorney general he has faith in,” he told reporters.

Sessions, for his part, earlier in the week fired back at Trump’s criticisms. The former Alabama Republican senator and once one of Trump’s biggest supporters on Capitol Hill said that as long as he is attorney general, the Justice Department’s “actions will not be improperly influenced by political considerations. I demand the highest standards, and where they are not met, I take action.”

David M. Axelrod, a political consultant who was a top Obama advisor, said that for Sessions, the writing is on the wall — or in his case, Trump’s Saturday Twitter messages.

“One way or another, he’ll remove Sessions, relieve [Deputy Atty. Gen. Rod] Rosenstein of control of Russia-related matters and try to strangle the Mueller probe and other actions he views as existential crises,” Axelrod tweeted.

Trump’s own potentially legal and political troubles mounted this week after Cohen, his longtime fixer, on Tuesday pleaded guilty to eight felony counts, including for violations of campaign finance laws that involved hush money payments to two women who claimed they had had affairs with Trump. Cohen said that he had acted “in coordination with and at the direction of” a man, clearly identifiable as Trump, “for the principal purpose of influencing the election” for president in 2016.

On the same day, a jury found Manafort guilty on eight counts of tax evasion and bank fraud. The Cohen case has put the spotlight on the Trump Organization’s finances, which could imperil the president and his family.

don.lee@latimes.com

Twitter: @dleelatimes