Here Are Some of the Prominent Surrogates at the Debate Site

The campaigns of Vice President Kamala Harris and former President Donald J. Trump said they would have an eclectic mix of recent converts and party-line-crossers at the debate in Philadelphia on Tuesday.

The Harris campaign invited Anthony Scaramucci, a New York Republican who had a memorable 10-day run as communications director in the Trump White House, and Olivia Troye, a former adviser to Mr. Trump’s vice president, Mike Pence.

Mr. Scaramucci and Ms. Troye, who have become outspoken Trump critics, held a news conference at the debate site to express their support for Ms. Harris earlier Tuesday.

The Trump campaign invited Robert F. Kennedy Jr., who last month suspended his quixotic, independent presidential run (which he had begun as a Democrat) and endorsed Mr. Trump, and Tulsi Gabbard, a onetime Hawaii congresswoman who ran for president in the 2020 Democratic primary.

The debate will not have a live audience, but the invitations seemed to be efforts by both campaigns to display a measure of cross-party appeal behind their candidates in a race that appears to be exceedingly close, according to polling.

Mr. Scaramucci, Ms. Troye, Mr. Kennedy and Ms. Gabbard are expected to be in a so-called spin room at the debate, which is being held at the National Constitution Center.

The campaigns also took along more typical surrogates.

For Ms. Harris, the group includes Gov. Josh Shapiro of Pennsylvania; Gov. Roy Cooper of North Carolina; Gov. Michelle Lujan Grisham of New Mexico; Gov. Gavin Newsom of California; Senator Laphonza Butler of California; Senator Tammy Duckworth of Illinois; Senator Chris Murphy of Connecticut; and several other members of Congress.

The group assembled by Mr. Trump includes Kristi Noem, thegovernor of