RICHMOND — State Sen. Frank Wagner (R-Virginia Beach) said Thursday that he would not seek reelection after 28 years in the Virginia legislature, joining a growing list of lawmakers who are retiring this year.

Wagner, 63, is the third Republican senator to bow out in a year when all 140 seats in the General Assembly are on the November ballot. Five delegates have also announced retirement plans — all but one from the GOP.

Republicans are defending razor-thin majorities in both chambers of the legislature, but the wave of resignations might not be a signal that they’re worried about hanging on. Recent scandals involving all three Democrats in the executive branch have given Republicans new hope, said longtime Virginia political analyst Robert Holsworth.

“I think it’s become far more uncertain what’s going to happen,” Holsworth said. In that light, he said, the resignations look more like coincidence.

The other senators who have announced plans to retire are Richard H. Black (R-Loudoun) and Bill Carrico (R-Grayson). While Carrico’s district in far Southwest is reliably Republican, Black’s has turned bluer in recent years as it has become more suburban. Republicans hold a 21-19 edge in the Senate.

On the House side, Republican Del. Steve Landes (Augusta) this week announced plans to seek a court clerk’s job instead of running for reelection. His district is heavily Republican, as are the districts of two other retiring delegates: Richard “Dickie” Bell (Staunton) and Gordon Helsel (Poquoson). Del. Riley Ingram (Hopewell), who will also retire, serves a right-leaning district that split evenly in the 2017 governor’s race.

The only Democrat to step down so far this year is Del. David Toscano (Charlottesville), the former House minority leader, who said he plans to spend more time with family.

The GOP has a 51-to-49 majority in the House.

Wagner and Ingram are the two most senior lawmakers to announce retirement this year, both having been elected to the House in 1992. Wagner switched to the Senate in 2000. He sought the Republican nomination for governor in 2017 but lost to Ed Gillespie.

Wagner’s Virginia Beach district went for Democrat Ralph Northam by 10 percentage points over Gillespie in 2017, but it split evenly between Donald Trump and Hillary Clinton in 2016. Wagner said in an interview that he was not stepping down out of concern about being reelected.

“In my district, there’s a lot more concern about the Democrats turning socialist, and angst over Trump is being superseded [by that],” he said. Wagner said he was ready to move on and that his family plans to live in a home outside his district.

He also said he’s not worried about Republicans losing their majorities, though he said the executive branch scandals are not a big factor in his district. Wagner even defended Northam, who has resisted calls to resign over a racist photo in his 1984 medical school yearbook.

Northam initially took responsibility for the photo, which shows one person in blackface and another in Klan robes. Then he disavowed the picture but admitted to darkening his face to imitate Michael Jackson in a dance contest that same year.

“My personal belief is things that went on in the ’80s reflect the times . . . and that people change,” Wagner said. He credited Northam for winning Medicaid expansion last year; Wagner was among a handful of Republicans who supported that effort.

Along with Northam’s problems, Attorney General Mark R. Herring has admitted wearing blackface for a college party in 1980, and Lt. Gov. Justin Fairfax has denied two separate allegations of sexual assault.

The scandals have drawn national attention, but all three men remain in office and could be liabilities for Democrats in this fall’s elections.