Remember this day, July 28, 2017. The day Donald Trump became a lame duck president. More significantly, the day the Tea Party revolution ended and Washington began the return to “regular order.”

The coup de grace came at 1:30 a.m. on the Senate floor as John McCain became the third Republican to break ranks and defeat the third and final attempt to repeal Obamacare, which embodied the Democrats’ promise that all American could — and should — have health insurance at a price they could afford. It was, as Tea Party Republicans had warned, another expensive government entitlement that, once granted, could never be taken away. Now John McCain had acknowledged that political reality.

Although it appeared to fall short by a single vote in the Senate, that was always going to be the margin of defeat for the seven-year effort to repeal Obamacare that had become the centerpiece of the Tea Party revolt. There were as many as 10 Republicans who had acknowledged that proposal cobbled together at the last minute by the Republican leadership was so bad that, earlier in the day, they had demanded assurances from the House of Representatives that it would never become law.

It was left to McCain, however, to do the deed so the others could protect themselves from the retribution of party leaders or the wrath of party Tea Party voters in the next Republican primary. Having just been diagnosed with brain cancer, the senior senator from Arizona had achieved that state of political liberation where he no longer had to worry about such things.

McCain was joined in his “no” vote by Republican Lisa Murkowski of Alaska, who earlier in the week had received a call from the secretary of the Interior warning that the administration would drop its support for expanded energy drilling and road construction in Alaska if she dared to defy the president and Republican leadership on the crucial vote. Murkowski did not take well to being muscled in that ham-handed fashion. As chair of the two relevant committees, she announced that she was indefinitely postponing sessions to consider nominations to Interior’s top positions and to mark up its 2018 appropriations.

The collapse of the Obamacare repeal effort was hardly the only evidence of the waning influence of Trump and his Tea Party supporters.

In the hours before the vote, the attorney general of the United States had defiantly declared he had no intention of acceding to White House requests that he resign and dared the president to fire him.

“If he wants to make a change, he can certainly do so,” Jeff Sessions told Fox News. The Republican chairman of the Senate Judiciary Committee, urged on by several Republican colleagues, had already warned the Republican president that anyone appointed to replace Sessions would not receive a confirmation hearing. And senators of both parties had indicated that they would use parliamentary slight of hand to keep the Senate in formal session through the normal summer recess to prevent Trump from replacing Sessions with a recess appointment.

Earlier in the day, military and civilian leaders at the Pentagon indicated they would “study” what to do about transgender members of the armed forces after the commander in chief had tweeted that they would no longer be allowed to serve.

And at the White House, the long-running tong war among members of the president’s top staff finally broke out into the open, as the new communications chief let loose with a profanity-laced rant against a chief of staff whom he characterized as a paranoid schizophrenic leaker and chief strategist who spent his days engaged in political self-fellatio.

Hoping to demonstrate, despite all the evidence to the contrary, that the business of government was proceeding apace, the White House and the Republican leadership of the House and Senate issued a five-paragraph “statement of principles” for a long-promised reform of the tax code. Months in the making, the statement was a nothing-burger of political and economic platitudes that failed to resolve the central challenge of reducing tax rates without reducing tax revenue and exploding the federal deficit.

This is a Waterloo moment for Trump, the Tea Party and their alliance. They have been stopped in their tracks not only by Democratic opposition, but because of a mutiny within their own ranks. Although never particularly liked or respected, it is now clear that they are no longer feared. The bankruptcy of their ideas and their incompetence has been exposed. Their momentum has been dissipated. Their rejection of political norms has itself been scorned. Our long national nightmare may finally be coming to an end.

Steven Pearlstein is a Washington Post business and economics writer, and Robinson Professor of Public Affairs at George Mason University.

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