The palace intrigue spilled into public with a vulgarity-laced rant by Anthony Scaramucci, the new White House communications director, who called Mr. Priebus a âparanoid schizophrenicâ and vowed to take him down. While aides fought with one another, Mr. Trumpâs signature promise to repeal and replace President Barack Obamaâs health care program went down in flames.
âAnyone in a position of responsibility in G.O.P. politics is quickly losing patience with President Trump,â said Alex Conant, a Republican strategist and former adviser to Senator Marco Rubio of Florida. âThe dysfunction is beyond strange â itâs dangerous.
âIf Trumpâs poll numbers were above 50 percent,â Mr. Conant continued, âhealth care reform would have passed. Instead, heâs spent more time responding to cable TV chatter than rallying support for his agenda.â
Presidential historians found it hard to recall precedents for the combination of internal warfare and external legislative troubles. Jeffrey A. Engel, the director of the Center for Presidential History at Southern Methodist University, said the best examples were John Tyler and Andrew Johnson in the 19th century. Both men were serving as vice president when their bosses died in office, each during a time of great turmoil in his political party.
âIn either case, we are forced to go well back over a century in the past to find an administration in such an open state of infighting coupled with legislative disarray,â he said.
Presidents can recover from a difficult first six months, as Bill Clinton did, Mr. Engel said. âBut certainly, like both Tyler and Andrew Johnson, we see today a president at war with his own party, and that to my mind never turns out well,â he said.
The repeated defiance of Mr. Trump this past week indicated diminishing forbearance. Attorney General Jeff Sessions, publicly derided by Mr. Trump as âVERY weak,â refused to resign under pressure. Senate Republicans forced the president to back off his threats by warning that they would block any effort to replace Mr. Sessions, either during their recess or through the confirmation process.
The House and Senate Intelligence Committees, both led by Republicans, summoned Jared Kushner, the presidentâs son-in-law and senior adviser, to Capitol Hill to explain his contacts with Russia during and after last yearâs campaign. With near-unanimous, veto-proof bipartisan majorities, Congress passed legislation curtailing Mr. Trumpâs power to lift sanctions against Russia, a measure the president had to swallow and agree to sign.
After Mr. Trump abruptly wrote on Twitter that he was barring transgender people from the military, the chairman of the Joint Chiefs of Staff declared that the policy would not change unless the president gave a proper order. The Boy Scouts of America condemned Mr. Trumpâs speech to its national jamboree as overly political and apologized to scouts, while some police organizations repudiated his call to be rougher on suspects.
And a Republican senator, John McCain, repaid Mr. Trumpâs 2015 insult to his war service by torpedoing the presidentâs health care agenda with a dramatic middle-of-the-night thumbs down vote on the Senate floor.
âThink about this week. Not once, not twice â any of these things would have been a nail in the coffin,â said Mayor Rahm Emanuel of Chicago, a White House chief of staff under Mr. Obama and a Democratic member of the House before that. âThey told the president to pound dirt. Thatâs an unbelievable statement on where his presidency is only six months in. And nobody fears the political repercussions.â
Indeed, Senator Lisa Murkowski, Republican of Alaska, received a call from Mr. Trumpâs interior secretary, Ryan Zinke, reportedly warning of repercussions for the state after her initial vote against proceeding with the health care debate. Undeterred, she voted against the president again on a bill to repeal parts of Mr. Obamaâs program.
Aides insisted the president would keep fighting.
âPeople are counting him out after health care,â Kellyanne Conway, a White House counselor, said on Fox News. âI would never bet against Donald Trump. Heâs not going to allow one misvote by the Senate to stop him to provide relief for all of these Americans who are suffering. Heâs not going to allow personnel changes to get in the way of tax reform or pushing back against these MS-13 gangs.â
Ms. Fagen said that tapping a general for the White House staff chief might be successful, but that it depended on whether he would be empowered in a way that Mr. Priebus had not been. Neither Mr. Trump nor Mr. Kelly disclosed what commitments if any were made to Mr. Kelly.
Mr. Priebus never had full command. Two senior advisers in the White House are immune from the discipline of a chief of staff: Mr. Kushner and Ivanka Trump, the presidentâs daughter. When Mr. Scaramucci, the brash new communications director, was hired over Mr. Priebusâs objections, he boasted that he reported directly to the president, not to the chief of staff.
Even Mr. Priebus agreed it was time for a change. âI think actually going a different direction, hitting a reset button is actually a good thing, and the president did that,â he told Fox News on Friday. âSo I think heâs happy, I got to tell you, although itâs always a little mixed when things like this happen.â
Mr. Kelly served as the senior military adviser to two defense secretaries, Robert M. Gates and Leon E. Panetta, and learned how to manage a sprawling operation with complicated politics. That gives hope to some.
âItâs not clear that John Kelly can succeed where Reince Priebus failed, because it appears that the president wants to act as his own chief of staff,â said Brian McKeon, who worked in Mr. Obamaâs White House and Defense Department. âBut given his background and experience, it seems likely that General Kelly will insist on a chain of command that runs through him, with no other staff reporting directly to the president.â
Ms. Conway said Mr. Kelly was a âgenerational peerâ with the president but dismissed questions about chain of command.
âThatâs just a pecking order question,â she said. âI think itâs beside the point, and hereâs why: We all serve the president and this country. And in doing so, the president and his new chief of staff will decide what the right organizational structure and protocols are.â
Anyone who has studied the White House, however, knows that organization can be key to success. Chris Whipple, the author of âThe Gatekeepers,â about White House chiefs of staff, said that Mr. Trumpâs White House was broken and that the president needed to enable Mr. Kelly to fix it.
âTrump now has a chance at governing, but it may be only a slim chance,â Mr. Whipple said. âThe fundamental problem is that Donald Trump is an outsider president who has shown he has no idea how to govern â who, more than any of his predecessors, desperately needs to empower a chief of staff as first among equals to execute his agenda and tell him hard truths.
âBut does anyone believe that this president wants such a person around?â