US Vice President Kamala Harris’s late entry into the White House race has galvanized young Democrats, a group whose participation will be crucial if the party hopes to defeat Donald Trump in November.

When President Joe Biden announced on July 21 — with two simple messages on X — that he was withdrawing from the race and endorsing Harris, 28-year-old Stevie O’Hanlon said she felt “relief.”

Concerns about the 81-year-old Biden’s mental acuity and his grim polling numbers against Trump had sparked “a sense of dread amongst many young people,” said O’Hanlon, a member of the youth climate activism group Sunrise Movement.