Gilstrap loses his Senate seat on Jan. 12 when his four-year term expires. Sebelius supported and helped raise money for his opponent in the Democratic primary, Sen.-elect Kelly Kultala, also from Kansas City.
In a statement, Gilstrap said the Democratic Party has shifted "radically to the left.''
Some Democrats argued Gilstrap voted with Republicans and was a Democrat only to increase his chances of getting votes in heavily Democratic Wyandotte County.
(Copyright 2008 by The Associated Press. All Rights Reserved.)