WASHINGTON — There wasn’t a dramatic public break or an exact moment it happened. But step by step, Senate Republicans are turning their backs on President Donald Trump.

They defeated an Obamacare repeal bill despite Trump’s pleas. They’re ignoring his Twitter demands that they get back to work on it. They dissed the White House budget director, defended the attorney general against the president’s attacks and passed veto-proof sanctions on Russia over his administration’s objections.

They’re reasserting their independence, which looked sorely diminished in the aftermath of Trump’s surprise election win.

“We work for the American people,” Sen. Tim Scott of South Carolina said Tuesday. “We don’t work for the president.”

Those are surprisingly tough words from a Republican whose state Trump won easily less than a year ago. But after six months of controversies and historically low approval ratings, it’s clear Trump isn’t commanding the fear or respect he once did.

Some Republicans no doubt are giving voice to long-held reservations about a man whose election was essentially a hostile takeover of their party. But it is notable that the loudest criticism is coming from the Senate, where few Republicans are burdened with facing an electorate anytime soon. The situation is different in the House, where most Republicans represent conservative districts still loyal to Trump. For those lawmakers, the fear of facing a conservative primary challenger, possibly fueled by angry Trump followers, is real.

In the most remarkable example of public Trump-bashing, Sen. Jeff Flake of Arizona is taking aim at the president and his own party in a new book, writing that “Unnerving silence in the face of an erratic executive branch is an abdication” and marveling at “the strange specter of an American president’s seeming affection for strongmen and authoritarians.”

The criticism from Flake is especially striking since he is one of just two GOP senators facing competitive re-election races in next year’s midterm elections, the other being Dean Heller of Nevada. The other 50 Senate Republicans are largely insulated from blow-back from Trump’s still-loyal base, at least in the short term, since they won’t face voters for several years.

That is likely contributing to their defiance, which is emerging now after an accumulation of frustrations, culminating in the failure of the health care bill Friday. In particular, senators were aghast over Trump’s recent attacks on their longtime colleague Jeff Sessions, the former Alabama senator who is now attorney general and facing Trump’s wrath over having recused himself from the investigation into possible collaboration between Russia and Trump’s presidential campaign.

Sen. Lindsey Graham of South Carolina deemed Trump’s treatment of Sessions “unseemly” and “a sign of great weakness on the part of President Trump.” The comments were echoed by other Republican senators.

Then, White House budget director Mick Mulvaney, a former House member, suggested on a Sunday show that the Senate must pass health care before doing anything else. No. 2 Republican John Cornyn didn’t hesitate to go after him.

“I don’t think he’s got much experience in the Senate as I recall, and he’s got a big job,” Cornyn said. “He ought to do that job and let us do our jobs.”

The ill will flows both ways. At Tuesday’s White House briefing, press secretary Sarah Huckabee Sanders pointedly blamed lawmakers for the president’s failures to deliver. “I think what’s hurting the legislative agenda is Congress’ inability to get things passed,” she said.