It's been 35 years since Ronald Reagan announced his run for president. He did so just two months before the Iowa caucuses, unlike the protracted campaigning that takes place today. WJZ/AP hide caption

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A protester in front of Sen. Marco Rubio's Doral, Fla., office in 2013 urges Rubio to stop opposing the inclusion of lesbian, gay, bisexual and transgender families in the Senate's immigration bill. Joe Raedle/Getty Images hide caption

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Marco Rubio celebrates onstage with his family in 2010 after winning his U.S. Senate seat in Florida when he was just 39 years old. Now, he's expected to embark on a run for president. Alan Diaz/AP hide caption

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Canadian athletes hold up the national flag during the 2014 Winter Olympics in Sochi, Russia. Sen. Ted Cruz was born in Calgary, and some question his eligibility to run for president in the U.S. Darron Cummings/AP hide caption

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Sen. Ted Cruz, R-Texas, arrives Sunday for a walk-through for his Monday speech at Liberty University in Lynchburg, Va., in which he is expected to formally launch his campaign for president. Andrew Harnik/AP hide caption

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Sen. Ted Cruz, his wife, Heidi, and their two daughters Catherine (left) and Caroline practice waving on stage at Liberty University before Cruz's Monday presidential campaign launch. Andrew Harnik/AP hide caption

itoggle caption Andrew Harnik/AP