President Trump was bluffing when he tweeted that he knows the successor to White House counsel Don McGahn, and instead he is vacillating about new legal leaders as he girds for open warfare with Democrats and Robert Mueller. The newest name on the president's mind: Fannie Mae general counsel Brian Brooks, two sources with direct knowledge tell me. 

Why it matters: This is, by far, Trump's most important current staffing decision. The climax of Mueller's probe lies ahead. And the White House faces the possibility of impeachment proceedings — and certainty of endless subpoenas and investigations — if Democrats win the House in November.

• In search of: Trump wants somebody who'll be unquestioningly loyal — who'll be "his guy" and defend him on TV, said a source familiar with his thinking. (McGahn fulfills neither criteria: He's independent-minded, TV-shy and makes no effort to disguise his contempt for Jared and Ivanka.)

Emmet Flood, the White House attorney dealing with Mueller's investigation, looked set to take the job.

• But Axios has learned that Trump is now seriously considering Brooks, a low-profile member of Washington's high-powered legal community.
• Brooks has been recommended by Treasury Secretary Steven Mnuchin, a friend from working together at OneWest, a California bank. Brooks was considered for deputy at Treasury, but withdrew from consideration for reasons that are still unclear.
• Flood is still very much in contention, along with Washington litigator Pat Cipollone, according to sources involved in the process.
• No decision is likely for a few weeks, one of those sources said.

Trump tweeted on Aug. 30: "I am very excited about the person who will be taking the place of Don McGahn as White House Councel [sic]!" 

• But Trump privately is still going back and forth, and he is even open to new names.
• Meanwhile, the White House Counsel's office is down to bare bones. McGahn is leaving soon, almost all of his deputies have departed and the office is nowhere near equipped for the storm that's likely coming.
• Another name that has been mentioned inside the White House as a possible McGahn replacement is Matt Whitaker. He's a former U.S. attorney for Iowa and has the disadvantage of being Jeff Sessions' chief of staff, but he's managed to maintain a good standing inside the White House despite Trump's hatred of Sessions.

The president's insistence on a loyalist could pose problems for Flood, who's by far the most qualified to handle a season of investigations:

• Flood is independent-minded. According to friends, he agreed to take his current job because he thought the special counsel and "culture of investigations" was out of control. He wanted to protect the presidency as an institution, as he'd done for Presidents Bill Clinton and George W. Bush.
• Trump and Flood have spoken about the job more than once, but Trump has never formally asked.
• Flood is telling Trump he would need to be able to hire the right people to run day-to-day business so he can continue to focus on Mueller.

Be smart ... A top Washington lawyer summed up the stakes: "If they lose [Flood] they are f---ed. Because they are never going to find a decent white-collar type to fill Emmet's shoes."