The leader of a Washington foundation is widely expected to become the newest member of Congress.

Donna Edwards, executive director of the Arca Foundation in Washington, is the favorite to win a June 17 special election to represent Maryland’s Fourth Congressional District.

Ms. Edwards, a Democrat, defeated Rep. Albert R. Wynn, who now holds the seat, in the Maryland primary in February.

Mr. Wynn has since decided to vacate his seat — a decision that is expected to allow Ms. Edwards to get a head start in Congress and solidify her effort to win the seat in November’s general election.

Ms. Edwards said during a recent speech at the Council on Foundations annual meeting that her experience in the nonprofit world will inform her decision making as a lawmaker.

“You’re going to have yet another friend on Capitol Hill,” Ms. Edwards told the foundation leaders.