ANCHORAGE — Jeff King, a four-time winner of the Iditarod Trail Sled Dog Race, is changing political teams when it comes to Alaska’s U.S. Senate race, pulling his endorsement of Republican incumbent Lisa Murkowski and backing independent candidate Margaret Stock.

King earlier this year appeared in a radio ad with two other mushers supporting Murkowski. But King told The Associated Press on Friday that he has changed his mind and is endorsing Stock. Stock sees herself as Murkowski’s main competition for the general election.

King cited as a reason his dissatisfaction with what he sees as the refusal by the state’s congressional delegation to stand up to Republican presidential nominee Donald Trump, whom he calls an embarrassment. King also said he was unhappy with Murkowski’s position on allowing President Barack Obama to appoint a U.S. Supreme Court nominee. Murkowski in February urged Obama to yield that appointment to the next president.

For similar reasons, he said he also wouldn’t support Republican Rep. Don Young, the other delegation member seeking re-election.

A Murkowski spokesman, Robert Dillon, said the campaign had no comment.

King said he has known Stock personally for years and cited her work as an attorney and her background in the military as assets.

Stock is a Harvard Law grad who served on active duty with the Army and in the Army Reserve. For several years she taught at the United States Military Academy at West Point, according to her bio. She was a 2013 MacArthur Foundation “genius grant” winner for her work on immigration issues.

Stock credits the kindness of people around her for helping her turn her life around from a high school dropout hit hard as a teenager by her father’s death. In a recent interview, Stock said people are frustrated with a Congress that’s dysfunctional because the two major parties are at odds and don’t cooperate.

Stock said she was previously a Republican but believes the party is no longer in line with her values, particularly on social issues. She said she won’t follow the dictates of a national party and will do what’s best for Alaska.

One of the challenges facing Stock is fundraising.

As an independent, she notes that she doesn’t have access to a party fundraising database or to the resources that the backing of a party can bring. She said she spends a lot of time calling people she knows to help raise money and will not take money from corporate political action committees.

As of July 27, Stock had about $110,000 available, while Murkowski had nearly $2.5 million. Libertarian Cean Stevens reported having about $3,600.

Murkowski, who won her last re-election bid as a write-in candidate with support from across the political spectrum, has cast herself as someone willing to work across party lines. She chairs the Senate energy committee, a post with significance for Alaska, and touts her willingness to take a serious, measured approach to issues.

The Democratic nominee in the race, Ray Metcalfe, has reported no fundraising with the Federal Election Commission and doubts he’ll get much support from his party.

Metcalfe, who has butted heads with leaders of his party, was left out of an email from party chairwoman Casey Steinau Thursday that congratulated Democrats who won their primary races and offered thanks to a few who lost. A message left for Steinau wasn’t immediately returned Friday.

As an independent, Stock bypassed the primaries but had to submit signatures to qualify for the November ballot. Verification of those signatures was pending, according to Alaska’s Division of Elections.

Follow Becky Bohrer at https://twitter.com/beckybohrerap .