April 15 is not usually a happy day. It’s the day our federal and state tax bills come due and a reminder of how much we already pay in taxes, even before the bill for Congress’s reckless spending spree comes due. But last year something changed. The Tea Parties made April 15, for me, one of the happiest days of the year. Why? Because it was the day Americans said they had had enough of big government and were ready to fight back.

Hundreds of thousands, possibly millions, of Americans took to the streets to protest. To protest not just taxes, but out-of-control borrowing, bailouts, pork-barrel corruption, and the fundamental unfairness of forcing people who worked hard and saved to pick up the tab for people who took risks that didn’t work out. The Tea Party announced itself as a powerful force in American politics, despite every effort of elites in New York and Washington to downplay, belittle, and insult it.

It started with Rick Santelli’s cathartic rant on CNBC, but it spread quickly to commonsense Americans all over the country who were fed up and took the time away from work and family to become a new generation of political leaders. And these folks were not self-serving leaders with personal ambitions, but patriotic leaders sacrificing their time and money to fight for the American ideals of limited government and personal responsibility.

These Tea Party leaders—some at the national level but most especially at the local level, in cities and towns large and small—have done something truly remarkable. I was amazed and impressed with last year’s Tax Day Tea Parties, but didn’t know if that level of energy could ever be reached again. I thought it was a high point, but I was wrong. It was just the beginning.

Activists took ownership of the health care debate, and very nearly stopped a bill designed to dramatically change the relationship between government and the people that otherwise would have sailed through Congress. Last summer became the summer of a grassroots uprising, and the momentum helped carry statewide candidates running on limited-government platforms to victory in Virginia, New Jersey, and most dramatically Massachusetts.

President Obama and Democratic leaders in Congress ignored the American people, stretched their parliamentary process nearly to the breaking point, and forced the hated health care bill through Congress anyway. They will have a terrible political price to pay, because the Tea Party movement is continuing to gain strength.

I expect that nearly every rally in the country today will top last year’s turnout numbers, setting new records. The American people will not back down in the face of a government that insists on forcing us to do what it thinks is best for us, while racking up trillions of dollars of debt that we, our children, and our grandchildren will eventually be forced to pay for.

The elite media and Democrats in Washington insist that Tea Party protesters have been misled into believing that their taxes have gone up. But I trust the wisdom of the American people, who correctly understand that the real tax burden is the level of government spending, which is already spiraling out of control. They know there are enormous tax hikes on the horizon that are set to kick in when the calendar turns to 2011. And they know that these taxes will keep rising if we continue on our present course.

A movement that has only grown stronger, even while facing adversity, over the past year will not go away over the next six months. The message to politicians in Washington, in state capitals, and local seats of power is clear: November is coming. And if you don’t discover and deliver fiscal responsibility, November is coming for you.

Phil Kerpen is vice president for policy at Americans for Prosperity. He can be reached on Twitter, Facebook, and through www.philkerpen.com.

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Phil Kerpen is the founder of American Commitment Action Fund, on the web at www.BookerFAIL.com.