Thousands of people turned out in support of GOP front-runner Donald Trump, who campaigned in Tampa Monday ahead of the primary election.

A line of people gathered outside the Tampa Convention Center ahead of the rally. Many wore their Trump gear, including the now-famous red "Make America Great Again" hats, while others were in Trump T-shirts.

About 4,000 supporters attended the rally, where they also heard former Alaska Gov. Sarah Palin, New Jersey Gov. Chris Christie and Florida Attorney General Pam Bondi speak in support of Trump.  The venue was so full that hundreds of Trump supporters had to be turned away at the door.

Most of his supporters tell us they say it's time for a change in the U.S., and the only way to do that is to bust up the entrenched establishment in Washington D.C. and to get the big money influence out of politics. Many are staunch supporters of his plan to build a wall to stop illegal immigration.

Crowds gather at the Tampa Convention Center Monday morning. (Holly Gregory, staff)

The top reason cited by his supporters, though? They like that he says whatever he thinks.

Supporters weren't the only ones who turned out at Trump's rally Monday. Protesters also lined up outside the Tampa Convention Center hours before the rally started. Things became heated between the two camps. The two sides argued back and forth, but things didn't get out of hand.

"His words are divisive," protester Maria Hays said. "They’re homophobic, they’re Islamophobic, they’re xenophobic, they’re misogynist, and that’s not what our country stands for."

Trump was in Boca Raton Sunday night. He was originally going to rally tonight in Doral, but that event was called off after he decided to go to Ohio tonight instead. Ohio is more of a battleground for Trump right now, as the latest polls show a dead heat race between Trump and Gov. John Kasich.

A couple of Trump supporters attended his rally at the Tampa Convention Center appearance Monday. (Holly Gregory, staff)

There's another reason, though - the campaign got wind of a large organized protest scheduled to happen in Doral.

As for the other GOP candidates, Florida Sen. Marco Rubio rallied in Pinellas County over the weekend. He addressed a few hundred supporters in Largo.

We asked Rubio was his plan was if he didn't win in Florida. He said he wasn't sure, but he believes whoever takes the Sunshine State will take the nomination.

Protesters gather outside the Tampa Convention Center, where Trump spoke Monday afternoon. (Holly Gregory, staff)

He's said more than once that if that person is Donald Trump, he'll have a hard time backing him.

Rubio is traveling down the east coast of Florida today with stops in Melbourne, West Palm and eventually Miami.

Ted Cruz is focusing his attention on Illinois and Kasich is in Ohio. Both of those states hold primaries tomorrow, as well as North Carolina and Missouri.

A lone protestor lets his message be known Thursday outside the Tampa Convention Center. (Holly Gregory, staff)

A pair of Trump fans show their support for their candidate ahead of his rally at the Tampa Convention Center Monday afternoon. (Holly Gregory, staff)