Candidates take their case to conservative conference February 10, 2012 -- Updated 1510 GMT (2310 HKT) Three of four GOP presidential contenders speak to CPAC on Friday Results of Maine caucuses to be announced on Saturday Romney tells technology forum that less regulation and lower taxes will spark innovation Washington (CNN) -- Three of the four remaining GOP presidential candidates will take their cases straight to conservatives on Friday with appearances at the Conservative Political Action Conference. Rick Santorum, Mitt Romney and Newt Gingrich were all scheduled to address the influential gathering in Washington. Only Texas Rep. Ron Paul was not on the agenda. Paul was invited but opted to stay on the campaign trail, according to the American Conservative Union, which hosts CPAC. Romney also plans to travel to Maine on Friday afternoon for a town hall meeting on the eve of the announcement of the winner of that state's GOP caucuses. On Friday morning, Romney spoke to the Northern Virginia Technology Council, delivering a speech focusing on "dramatic, bold, creative change," including fewer regulations and a tax structure that he said would encourage risk-taking to position the United States as the most innovative in the world. "If America is to remain the strongest nation on earth, then we must be the most innovative nation on Earth," Romney said before laying out what he said are autocratic challenges to U.S. preeminence in the world. Romney ends the week in a more tenuous position than he began it after Santorum swept the three Republican contests on Tuesday. Colorado was the most competitive state on Tuesday, with Santorum winning 40% of the vote to 35% for Romney, 13% for Gingrich and 12% for Texas Rep. Ron Paul In Minnesota, Santorum got 45% of the vote to 27% for Paul, 17% for Romney and 11% for Gingrich, according to the secretary of state. In Missouri, Santorum had 55% to Romney's 25% and 12% for Paul, according to unofficial results. Gingrich didn't make the ballot there. Santorum's victories in two states Romney won in his unsuccessful 2008 presidential bid -- Colorado and Minnesota -- signaled both his growing support and Romney's inability to build on the momentum from victories in the two previous contests in Florida and Nevada. They also helped Santorum in the fund-raising department. The Super PAC that supports Santorum, the Red, White and Blue Fund, has seen increases in contributions and pledges since Tuesday night. "We've been working at a speed faster than any other day the super PAC has seen in this election season," Stuart Roy, a spokesman for the PAC, told CNN. Romney's campaign promised to challenge Santorum more directly following Tuesday's results, and followed through Thursday by attacking the former Pennsylvania senator as a Washington insider. Romney accused Santorum and Gingrich -- the former Republican House Speaker -- of behaving more like Democrats during their time in office. Romney said in Atlanta, "Under Newt Gingrich earmarks doubled. Rick Santorum was a major earmarker and continues to defend earmarks. Following Saturday's announcement of the winner in Maine, the GOP contest to take on President Barack Obama moves to Arizona and Michigan on February 28.