PORTLAND — Vice President Joe Biden called on a group of Jeff Merkley supporters Wednesday to re-elect the first-term senator so that Democrats can help rebuild the middle class.

Biden’s speech focused on the lost wealth of America’s workforce during a free Merkley rally at the Oregon Convention Center in Portland.

“We have to clear them out of the way, these guys,” Biden said, referring to national Republicans. “We have to win. We have to win for the American people.”

While talking to a crowd consisting of large groups of public employees, Biden touched on a wide array of progressive issues, including maintaining unions that have come under attack in some corners of the U.S.

“The middle class is what built this country,” Biden said. “And, I might add … unions built the middle class.”

Republican challenger Monica Wehby, a pediatric neurosurgeon, undercut the vice president’s visit by sending an open letter to Biden just hours before he spoke.

Wehby wrote that Biden and Merkley’s agenda is “what’s responsible for an increase in our poverty, a decrease in our incomes, and the destruction of the American middle class.”

Sen. John McCain, R-Arizona, visited a week ago and asked a group of Wehby supporters to elect Wehby so Republicans have a majority in both houses of Congress.

Democrats are considered vulnerable to losing their three-seat lead in the Senate, and Republicans are likely to maintain a big lead in the House after the November election.

The latest poll put Merkley 13 points ahead of Wehby headed into October. Oregon starts mailing out ballots Oct. 15, the day after the voter registration deadline.

— Taylor Anderson, The Bulletin