The Service Employees International Union has made some post-election changes to its political shop.

Jon Youngdahl, SEIU’s political director, will become the union’s next chief of staff. He will be replaced by Brandon Davis, SEIU’s deputy political director for national field campaigns.

Until 2009, Davis worked for the union’s state affiliates in Kansas and Missouri, and as political director for the Missouri State Democratic Party and the campaign of Sen. Claire McCaskill (D-Mo.).

“Under [Davis’] leadership, SEIU members were able to win almost 48 percent of our key races in one of the toughest elections for progressive organizations in recent memory,” SEIU spokesman Mark McCullough wrote in an e-mail Monday. He added that Davis’ grass-roots operation turned out more than 2,100 members to knock on doors in California and “produced 20,000 GOTV phone calls in Connecticut and 300,000 in Illinois, just to name a few of the races where SEIU members really made a difference.”