Karger's share of the vote -- about 1.4 percent -- landed him in fifth place in the U.S. territory, which delivered a landslide win to former Massachusetts Gov. Mitt Romney.
But underdog Karger, the only openly gay candidate in the GOP race, saw much to celebrate in results. In addition to topping his previous finishes for percentage of votes won, he finished ahead of Texas Rep. Ron Paul.
"I had no idea the outpouring of support," Karger said in an interview Monday, calling the results "incredibly gratifying."
Karger attributed his performance in Puerto Rico to the time spent on the ground in the week ahead of Saturday's votes, meeting with LGBT leaders, voters and members of the media, and and a Spanish-language commercial aired by his campaign. Puerto Rico's open primary, which allowed Democrats and Independents to cast ballots in the Republican race, also gave the pro gay marriage, pro-choice candidate a boost.
"The hard work, the media, the contacts and time spent here paid off," Karger, a political consultant who was a major player in the campaign against California's Proposition 8, said.
Karger focused much of his time and energy ahead of the start of the election season in New Hampshire, where he came in eighth place with just under 500 votes. Michigan is the only other state in which he has competed so far.
Karger said he hopes his showing will help his efforts to be included in any debates added to the schedule. But for now he's heading back to his home in California, then making stops in Las Vegas and New York to meet with GOP groups and media before heading to Maryland to campaign for the April 3 primary there.
Karger is also considering waging a write-in campaign in North Carolina, where he says he was denied ballot access. He hopes to contrast his pro gay marriage stance with a constitutional amendment banning gay marriage that will also be on the ballot there May 8.
But he said he is also trying to save the roughly $25,000 a month his campaign is bringing in so he can finish strong in June contests in California and Utah.
"I do all the things the big campaigns do on a limited budget," Karger said. "I'm trying to show that you can wage a campaign without $50 million or $100 million to do it."
PHOTO CREDIT: Fred Karger. Sacramento Bee file, 2010.