(CNN) - It's April 15, the traditional deadline day for Americans to file their tax returns. And for the third straight year, it's also a day when Tea Party activists across the country gather to protest what they consider unfair federal tax rates.
But two things make this year different.
With the battle for the Republican presidential nomination underway, many probable and possible GOP White House candidates will make sure they're front and center at some of the these Tea Party rallies. And secondly, this year the Internal Revenue Service approved April 18 as the tax filing deadline for 2010 tax returns and extension requests, in observation of Emancipation Day in the District of Columbia, which this year falls on April 15. That gives Tea Party activists a four day window to hold gatherings.
The most covered event Friday may be Americans for Prosperity's third annual Taxpayer Tea Party rally at the state house in Concord, New Hampshire. The Granite state holds the first primary in the presidential and caucus calendar. That may be one reason why former Minnesota Governor Tim Pawlenty, former Sen. Rick Santorum of Pennsylvania and former Godfather's Pizza CEO and radio talk show host Herman Cain all will speak at the gathering.
Pawlenty heads from New Hampshire south to neighboring Massachusetts later in the day to headline another tax day event, put on by the Greater Boston Tea Party. Not to be outdone, Cain heads much further south, to Florida, where he's scheduled to speak at a Tea Party gathering in Orlando.
Also in the Sunshine state Friday is former Massachusetts Gov. and 2008 Republican presidential candidate Mitt Romney. He speaks to taxpayers at an H&R Block branch in Orlando. In an op-ed in Friday's Orlando Sentinel, Romney praised the two year old movement, saying "thanks to the Tea Party, there's real hope that we can rein in our profligate federal government."
The action continues Saturday, with Rep. Michele Bachmann of South Carolina appearing at a Tea Party gathering in South Carolina, which holds the first southern primary in the road to the White House. Bachmann also speaks at a Tax Day rally at the state capitol in Columbia on Monday.
While Bachmann is a darling of many Tea Party activists, she'll have to share the spotlight this weekend. Former Alaska Gov. Sarah Palin speaks to a Tea Party rally in Madison, Wisconsin Saturday afternoon. The 2008 GOP vice presidential nominee is not ruling out a bid for the White House. Around the same time Donald Trump goes before cameras at a Tea Party rally in Boca Raton, Florida. The real estate mogul says he'll decide by June on whether he'll run for the Republican presidential nomination.
It's no surprise that so many potential Republican presidential hopefuls are making sure they show up at these events. The Tea Party movement was extremely influential in the GOP primaries in last year's midterm elections and there's no reason to believe that it won't play a major role in determining the party's presidential nominee next year.
–Follow Paul Steinhauser on Twitter: @psteinhausercnn