LYNCHBURG, Va. (AP) -- Sen. Ted Cruz opened the first major campaign of the 2016 presidential season Monday with a kickoff speech courting cultural conservatives and declaring that he will devote himself to "reigniting the promise of America."

One of several Republican hopefuls to rise from the tea party movement, Cruz spoke at Liberty University, the college founded by the late Rev. Jerry Falwell, hours after a wee-hours tweet announcing his White House bid. The choice of the college founded by the late Rev. Jerry Falwell was meant as marker against potential rivals who are also counting on Christian conservatives to fuel their candidacies.

Cruz addressed his religious faith, his father's Cuban roots and his unquestioned conservative credentials, saying "for so many Americans the promise of America seems more and more distant."

And he asked the enthusiastic crowd to "imagine a president that finally, finally, finally secures the borders."

"Imagine a simple flat tax," he said. "Imagine abolishing the IRS."

He spoke on the fifth anniversary of President Barack Obama's health care law - legislation that prompted Cruz to stand for more than 21 hours in the Senate to denounce it in a marathon speech that delighted his tea party constituency and other foes of the law. Cheers rose in the hall when Cruz reminded the crowd Monday that Liberty University filed a suit against the law right after its enactment.

"God's blessing has been on America from the very beginning of this nation and I believe that God isn't done with Americans," Cruz said. "I believe in you. I believe in the power of millions of courageous conservatives rising up to reignite the promise of America. And that is that is why, today, I am announcing that I am running for president of the United States of America."

Cruz, a divisive figure in his own party, is not expected to be the sole GOP contender for long. Former Florida Gov. Jeb Bush, Wisconsin Gov. Scott Walker and two Senate colleagues, Kentucky's Rand Paul and Florida's Marco Rubio, are eyeing campaign launches soon.