Swim said the Palin nod had been in the works "for a few months" and gathered steam in recent days when a Utah Policy Poll showed Matheson's support below 50 percent. He also said conservative commentator Dick Morris served as a facilitator between Palin's people and the Philpot camp.
The poll shows Matheson, seeking a sixth House term, up 46 percent to Philpot's 30 percent with 20 percent undecided. According to the survey, whenever an incumbent drops below 50 percent, a challenger can take that as a good sign.
And so, too, apparently, can Palin.
"Sarah Palin has typically not been the first endorsement for a candidate, but she has quite a track record of identifying candidates who are moving up and doing well and then helping them across the finish line," Swim said. "It shows we have momentum and that Jim Matheson is a candidate in free-fall."
There was no immediate comment from the Matheson campaign.
The Utah Policy Center/Western Wats poll shows Philpot has a lot of ground to make up, and Swim did say the campaign still needed to raise money.
"That's our task now," Swim said. "To convert that into raising dollars."
The Philpot campaign has been outraised and outspent by Matheson handily. According to the Federal Election Commission, as of June 30, Matheson had more than $1.35 million in receipts to $112,323 for Philpot.
Palin's Facebook endorsement urged voters in 2nd District to support Philpot as "a reliable, conservative leader for Utah."
"We can count on Morgan to make the right choices to bring our country back," the endorsement read.
Swim said the endorsement makes Philpot an official tea party candidate, and he argued that would generate more enthusiasm to unseat Utah's lone Democrat in Congress.