WASHINGTON (AP) - As the Republican Party struggles to broaden its appeal, the GOP's most prominent voices - past and potential presidential candidates among them - are joining thousands of conservatives and tea party activists this week outside Washington. The Conservative Political Action Conference offers Republican leaders a high-profile stage to court their party's most passionate voters. The speaker list is a who's who of possible 2016 Republican presidential contenders: Florida Sen. Marco Rubio, Louisiana Gov. Bobby Jindal, Kentucky Sen. Rand Paul, former Florida Gov. Jeb Bush and Wisconsin Gov. Scott Walker, among them. Both Rubio and Paul are scheduled to speak Thursday as the gathering begins at Maryland's National Harbor, just south of Washington. The conservative conference comes at a critical time for the GOP, still plagued by infighting after a painful 2012 election season. Party leaders next week will release a comprehensive plan - dubbed the Growth and Opportunity Project - to help improve the Republican brand. "The current disarray is actually pretty healthy," said former House Speaker and presidential candidate Newt Gingrich, who is scheduled to speak on the final day of the three-day conference. Gingrich said the conference gives the party an opportunity to have "a serious dialogue about where we're going." "I think the future of the party is to focus on a better American future - not to focus on being anti-Obama," he said. But the conference will likely attract the Republican Party's most aggressive critics of President Barack Obama. And Thursday's program offers a clear reminder that the GOP's future is unclear, as one side pushes for conservative purity while the other works to attract independents and the growing bloc of minority voters that fueled Obama's re-election. Rubio is set to speak Thursday afternoon, followed by Paul. The Republican senators spoke in the same order a month ago following Obama's State of the Union address. Rubio, a Republican who favors a more forgiving national immigration policy, delivered the GOP's formal response, while Paul followed with a response on behalf of the tea party movement. This week's Republican confab comes as Democratic activists gather in Washington to discuss a nonprofit group designed to promote Obama's agenda. Separately, the president planned meetings with members of Congress from both parties to push his legislative priorities. The nonprofit group, Organizing for Action, plans to raise millions of dollars to build support for Obama's agenda on issues like gun control, immigration and climate change. The group, led by former White House officials and top campaign staffers, is an attempt to harness the energy of the grass-roots machine that powered Obama's re-election campaign. "For every lobbying group that puts a dollar on the air, tearing down the president's agenda, an OFA volunteer will mobilize across the country to counter that," said Jim Messina, who managed Obama's re-election campaign and now serves as the group's chairman. Despite the hardball tactics on the left, Obama has projected an interest in striking deals with Republicans on immigration, gun legislation and cutting the nation's debt. The president was making three trips to Capitol Hill this week and planned to meet Thursday with Senate Republicans and House Democrats. Conservatives are scheduled to address the same policy debates, although it's unclear whether they'll be calling for compromise with Democrats. New Jersey's Republican Gov. Chris Christie, thought to be weighing a presidential bid, wasn't invited to the conference following conservative criticism after he enthusiastically praised Obama's hurricane response last fall. Former Alaska Gov. Sarah Palin and reality show star Donald Trump will appear, however. Trump took to Twitter to express his excitement over the reaction to his announcement that he would participate: " (at) CPACnews had its largest ever ticket sales the day of my announcement. Really an honor. Can't wait to see everyone," he wrote.