Republican members of Congress said nothing when President Trump told minority congresswomen to "go back" to where they came from.

Trump tweeted this morning that "Progressive Democrat Congresswomen" should "go back and help fix the totally broken and crime infested places from which they came."

Trump was almost certainly talking about the group popularly known as "the squad" — Ilhan Omar of Minnesota, Alexandria Ocasio-Cortez of New York, Ayanna Pressley of Massachusetts, and Rashida Tlaib of Michigan.

WaPo's Phil Rucker points out that "three of the four members of 'the squad' were born in the United States, so they would 'go back' to Cincinnati, Detroit and New York." (Omar was born in Somalia and came to the U.S. as a refugee.)

Between the lines: Trump knows he can say whatever he likes and face no consequences from the party he has conquered.

The few Republicans who dared to defy him either got crushed by pro-Trump candidates in primaries (Rep. Mark Sanford), quit the party (Rep. Justin Amash) or retired (Sens. Jeff Flake and Bob Corker). One remaining critic, Sen. Mitt Romney, mostly pushes back by issuing stern but ineffectual tweets. And Sen. Ben Sasse, who used to lambaste the president, has mostly gone silent.

No modern president, besides George W. Bush immediately after the 9/11 attacks, has enjoyed such popularity with Republican voters.

What's new: Tim Alberta, the chief political correspondent for Politico Magazine, has a book out this week that documents Trump's conquest of the Republican Party — the domination evidenced above.

Axios obtained an advance copy of the book, "American Carnage," which is deeply reported and engrossing. The book reveals Trump's delight in tormenting Republicans who he views as weak or disloyal, and it helps explain the partywide silence on days like today.

Two exclusive excerpts are especially revealing

1. The tormenting of Diane Black

"Not everyone was lucky enough to land Trump's support. Diane Black, the Tennessee congresswoman, was running in a crowded GOP primary to become the state's governor.

During a meeting with several House Republicans ... she pulled the president aside. 'You really need to endorse me,' she told him, stabbing a finger at his chest. Trump found her rude and presumptuous. 'She got in my personal space,' he told aides afterward. 'Big mistake.' ....The White House political director Bill Stepien ... asked an intern to aggregate a full record of everything Black had ever said about Trump, good and bad. The list was printed out and carried over to the Oval Office.

Trump scanned the document, picking out the negative remarks, then pulled out a Sharpie. 'Diane,' he wrote. 'This is NOT good!' He furiously underlined the word 'NOT,' then asked Stepien to hand-deliver the document to Black.

[Note: Black lost in the Republican primary race.]"

2. The tormenting of Erik Paulsen

"In one case, Trump endorsed as a means of punishment. Having heard that Minnesota congressman Erik Paulsen was distancing himself from the White House in the hope of holding his seat in the Twin Cities' suburbs, the president stewed and asked that the political shop send a tweet of support for Paulsen — thereby sabotaging the moderate Republican's efforts.

When his aides demurred, Trump sent the tweet himself, issuing a 'Strong Endorsement!' of the congressman in a late-night post that left Paulsen fuming and his Democratic opponent giddy. [Note: Paulsen lost his re-elect.]"

