More than 200 Bush, McCain and Romney alums back Harris

Flashback: Several dozen George W. Bush, Romney and McCain staffers united behind similar initiatives to elect President Biden in 2020, but this year, at least five former staffers of George H.W. Bush also signed on to the letter, which was first published Monday by USA Today.

Zoom in: Despite "honest, ideological disagreements" with Harris and her running mate, Gov. Tim Walz, the group of Republicans wrote, "the alternative is simply untenable."

• They warned of the national security threat they believe Trump and "his acolyte" Sen. JD Vance (R-Ohio) pose, contending the democratic movement abroad will be "irreparably jeopardized" as the members of the GOP ticket "kowtow to dictators like Vladimir Putin."
• The group wrote that "it was moderate Republicans and conservative independents in key swing states that ultimately delivered the presidency to Joe Biden," calling on them to "take a brave stand once more."

The other side: "They would rather see the country burn down than to see President Trump successfully return to the White House to Make America Great Again," Trump campaign spokesperson Steven Cheung said in a statement, contending, "It's hilarious because nobody knows who these people are."

The intrigue: Signers include Jean Becker, George H.W. Bush's longtime chief of staff, and David Garman, the former assistant secretary of energy under the George W. Bush administration.

The bottom line: Independents have emerged as the dominant voting bloc in American politics, and there has been a concerted effort to court those voters leading up to an election set to be determined by razor-thin margins.

• Among independents and voters affiliated with other parties, Biden led Trump by 52%-43% in 2020, according to Pew data.

Go deeper: Arizona Republicans back Harris at Democratic convention

Editor's note: The story has been updated with comment from the Trump campaign.