Rep. Don Beyer (D-Va.) is set to become the next national finance chairman of the Democratic Congressional Campaign Committee, he told The Washington Post Wednesday. He will succeed Rep. Chris Van Hollen (D-Md.), who is running for the U.S. Senate.

Beyer, who in 2014 won a Northern Virginia-based seat long held by Democrat James P. Moran, is a former ambassador to Switzerland and Liechtenstein who has strong ties to the Democratic donor class. He was an early backer of President Obama, who tapped him to become ambassador after he was elected president.

In an interview, Beyer said his role as the top fundraiser on the committee will involve a combination of convincing fellow Democratic members to pay their DCCC dues and reaching out to donors. The DCCC is the campaign arm of the House Democrats.

"I will be trying to make the case that if we want to pass legislation that we really believe in, we're going to need to be closer to 218 members," he said.

Beyer will step in for Van Hollen, who is running for the seat of retiring Sen. Barbara A. Mikulski (D-Md.). Rep. Donna Edwards (D) is facing off against Van Hollen in what is shaping up as a competitive primary.

Beyer said he was "optimistic" about 2016 election, even as most observers expect House Republicans to retain their wide majority.

"In a perfect world we'll get 30 seats and get the majority," he said. "But even if we only get 20 seats or 18 seats or 22, we're moving in the right direction."