UPPER MARLBORO, Md. (AP) — Prince George’s County Executive Jack Johnson says he plans to switch sides and vote for Sen. Barack Obama at the Democratic Party’s national convention in August.

Johnson tells The Washington Post he can’t in good conscience go to the convention and not support Obama. He says Hillary Clinton ran a great campaign but fell short.

Johnson is not a superdelegate. He is a pledged delegate for Clinton, but Maryland Democratic Party spokesman David Paulson says pledged delegates are under no obligation to stick with their candidate.

This is the second time Johnson has switched sides. He allowed his name to be used as an Obama supporter in December, then endorsed Clinton a few days before the Maryland primary in February.