John Bolton airing TV ad attacking Angela Alsobrooks

The ad looks like any political TV attack ad: Gray, grainy images. Big, bold words that convey negative information. Pictures of scary, rogue international leaders.

The ad, which began airing this week, targets Prince George’s County Executive Angela Alsobrooks, the Democratic nominee for U.S. Senate. But it doesn’t come from Alsobrooks’ Republican opponent, former Gov. Larry Hogan.

Instead, it’s paid for by the John Bolton PAC, the political action committee of John Bolton, former...