Former Democratic presidential candidate Hillary Clinton on Friday endorsed Denver Mayor Michael Hancock in his bid for a third term.

“Watching the mayor’s race in Denver and pulling for @MayorHancock-he’s a proven progressive leader who will work hard for Colorado,” tweeted the 2016 Democratic presidential nominee, former secretary of state and two-term first lady.

Hancock is facing a June 4 runoff against first-time candidate Jamie Giellis, an urban planner and past president of the River North Arts District.

Clinton won Colorado’s electoral votes in 2016, defeating Republican nominee Donald Trump by about 5 percentage points, but she lost the state’s Democratic caucuses earlier that year to U.S. Sen. Bernie Sanders of Vermont, who prevailed with 60% of the vote.

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The endorsement isn’t a surprise. Hancock was a high-profile Clinton backer and threw his support behind her for the nomination at the 2016 Democratic National Convention, where he was a super-delegate.

“Mayor Hancock is excited about the endorsement from Secretary Clinton,” Hancock campaign communications director April Valdez Villa said in a statement to Colorado Politics.

“He was proud to campaign for her in 2016, and he is ecstatic she is supporting him in this election. Mayor Hancock and Secretary Clinton are both proud, progressive leaders who share a record of fighting for people who most need someone in their corner.”

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It isn’t the first time Democrats with White House aspirations have waded into this year’s Denver mayor’s race.

John Hickenlooper, a former governor and two-term mayor of Denver, endorsed Hancock before the runoff and showed up Monday at a Hancock press conference to reiterate his support.

And Pete Buttigieg, the mayor of South Bend, Indiana, who has recently enjoyed a surge in the polls, on May 1 gave Hancock his blessing in a video posted online. 

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Giellis, a newcomer to politics, has plenty of endorsers – though none as high-profile as those backing Hancock, who was first elected to Denver City Council in 2003.

In a statement to Colorado Politics, Giellis said: “While Mayor Hancock is spending his time chasing endorsements from career politicians, as an experienced urban planner I am listening to Denver residents and talking to them about the everyday issues that impact their lives.

“This campaign is about putting people and neighborhoods first. I’ll take experienced Denver leaders such as Dr. Lisa Calderón and Penfield Tate over Hillary Clinton any day of the week.”

Calderón and Tate trailed Hancock and Giellis in the May 7 general election. This week, both endorsed Giellis for the runoff.

Among her other supporters: former Gov. Dick Lamm and his wife, Dottie, a one-time Democratic nominee for the U.S. Senate; former Denver Auditor Dennis Gallagher; state Reps. Adrienne Benevidez and Dafna Michaelson Jenet, both of Adams County; and former state Sen. Rob Hernandez of Denver.

Ballots go out Monday to Denver voters, who have until 7 p.m. June 4 to return them to election officials or cast their votes at numerous election centers set to open across Denver next week.