Former president Bill Clinton has endorsed L.A. mayoral candidate Wendy Greuel, wading into a competitive race that could launch one of the next Democratic rising stars.

“Wendy has personified good, honest and effective government, improving the lives of countless Angelenos while saving millions of their tax dollars,” Clinton wrote of the city controller in a letter first obtained by the Los Angeles Times. "She knows how to make government work for ordinary people, and she's been doing it for decades, not only when times are good, but especially during periods of crisis."

After finishing second in a close March 5 election, Greuel will face City Councilman Eric Garcetti in a May 21 runoff. If she wins, she will be the city's first female mayor. Technically, the mayor’s race is nonpartisan. But Los Angeles is a heavily Democratic city, and both Garcetti and and Greuel identify with the Democratic Party. The winner will succeed term-limited Antonio Villaraigosa, a Democrat believed to have national political ambitions.

Greuel served as an aide to Housing Secretary Henry Cisneros in Bill Clinton's administration. In his letter, Clinton says he was a "valued member" of the administration's team lauds her role in dealing with the aftermath of the 1994 Northridge Earthquake. Greuel later moved to DreamWorks, where she organized fundraisers for him. She endorsed Hillary Clinton in the 2008 election; Garcetti was an early backer of President Obama in that race.

Clinton has shown himself to be unafraid of meddling in Democratic primaries, often to reward politicians who have been loyal to his family.