The Atlantic's McKay Coppins is out with the first excerpt of his highly anticipated biography of Sen. Mitt Romney (R-Utah), timed to the 2012 GOP presidential nominee's announcement today that he will not seek re-election.

Why it matters: Romney — the only GOP senator to vote to convict former President Trump in his first impeachment trial — was brutally honest about his Republican colleagues over the course of two years of interviews with Coppins, a fellow Utahn.

Highlights:

• On Jan. 2, 2021, Romney texted Senate Minority Leader Mitch McConnell (R-Ky.) to warn about extremist threats law enforcement had been tracking in connection with pro-Trump protests on Jan. 6. McConnell never responded.
• Romney kept a tally of the dozen-plus times that Republican senators privately expressed solidarity with his criticism of Trump. "You're lucky," McConnell once told him. "You can say the things that we all think."
• Romney shared a unique disgust for Sens. Josh Hawley (R-Mo.) and Ted Cruz (R-Texas), who he thought were too smart to believe Trump won the 2020 election but "put politics above the interests of liberal democracy and the Constitution."
• He also was highly critical of Sen. J.D. Vance (R-Ohio), who reinvented his persona to become a Trump acolyte after publishing a best-selling memoir about the working class that Romney loved. "I don't know that I can disrespect someone more than J. D. Vance," Romney said.

Zoom in: After House impeachment managers finished a presentation about Trump's efforts to pressure Ukraine to investigate the Bidens, McConnell told Romney: "They nailed him."

• Taken aback, Romney said Trump would argue he was just investigating alleged corruption by the Bidens — the subject of House Republicans' present-day impeachment inquiry.
• "If you believe that," McConnell replied, "I've got a bridge I can sell you."

The bottom line: Romney said he never felt comfortable at a Senate GOP conference lunch after voting to convict Trump in 2020. "A very large portion of my party really doesn't believe in the Constitution," he told Coppins a few months after Jan. 6.