U.S. Sen. Dick Durbin on Sunday endorsed Paul Vallas in his bid to become Chicago mayor, giving Vallas a potential boost in the race for City Hall’s top job.

“He is a thoughtful leader who can strengthen Chicago’s economy and create jobs. He will be a mayor for all of Chicago and will move the city forward,” Durbin said in a news release. “With his focus on safer neighborhoods, improved schools, and economic growth, I am proud to stand with Paul, and urge all Chicagoans to support his election on April 4.”

The endorsement from Durbin, the second highest ranking Democrat in the Senate, could help Vallas shore up support from moderate or liberal voters who are concerned by Vallas’ association with conservative political figures and donors.

While Vallas has campaigned as a lifelong Democrat, he has faced questions about his associations with Republican activists and donors, as well as the right-wing Fraternal Order of Police. Durbin’s statement in a campaign news release repeats the “Paul Vallas is a lifelong Democrat” quote as its first line.

Vallas’ own words have caused problems for him as well. In a 2009 interview with Jeff Berkowitz, Vallas declared, “I am more of a Republican than a Democrat now,” a comment that has been featured in negative commercials from his rival in the April 4 runoff election, Cook County Commissioner Brandon Johnson.

Vallas has countered by saying he has a long record of supporting abortion rights, ran for governor in the 2002 Democratic Party primary against later-disgraced Gov. Rod Blagojevich and served as then-Gov. Pat Quinn’s running mate in his losing race against Republican Bruce Rauner in 2014.

Vallas has also acknowledged he considered running for Cook County Board as a Republican in 2009. But he said it wasn’t about the political party. Instead, Vallas said, he wanted to find a foothold to take on then-Board President Todd Stroger, who came from a powerful Democratic family and whose father, John Stroger, headed the Cook County Board for 11 years.

The endorsement from Durbin is also notable as recent news reports revealed how Vallas ridiculed him and Illinois’ other U.S. senator, Tammy Duckworth, for “always” casting yes votes for Democratic initiatives.

For his part, Johnson recently unveiled plans for a preelection rally with U.S. Sen. Bernie Sanders and announced endorsements from U.S. Senator Elizabeth Warren and U.S. Rep. Ayanna Pressley, all progressive stalwarts who will help boost his base.

Sanders has also been a proven vote-getter in Chicago, receiving 226,854 votes in the city during the 2020 Democratic Presidential primary.