Joe Biden’s gaffes are starting to grate on some Democratic insiders, who fear they’ll become easy fodder for President Trump to lob against the former vice president should he claim the party’s presidential nomination.

Concerns over the 76-year-old former vice president’s performance on the campaign trail recently began trickling down to members of the Democratic National Committee, many of whom are headed to San Francisco next week to hear from White House hopefuls at the body’s annual summer meeting.