Chris Carlson, AP
Republican presidential candidate, Sen. Marco Rubio, R-Fla., addresses supporters during a rally on Monday, Dec. 14, 2015, in Las Vegas. (AP Photo/Chris Carlson)

LAS VEGAS — Republican presidential candidate Marco Rubio rallied supporters in Nevada a day before a debate in Las Vegas, saying President Barack Obama's policies on health care, national security and the environment were putting the American Dream further out of reach.

Campaign officials said about 300 people attended the rally at the Renaissance hotel in Las Vegas.

The Florida senator highlighted his family's humble beginnings and southern Nevada roots, and touted his work to weaken Obama's health care overhaul through legislation preventing a multibillion-dollar "bailout" of insurance companies that lost money by participating.

"Everyone running for president as a Republican is against Obamacare," Rubio said to cheers. "But I'm the only one running who has ever scored a victory over Obamacare."

He also criticized a U.S. agreement with China to cut emissions, saying America would bear the cost of new environmental regulations if China drops the ball.

And he slammed Obama for a speech after attacks in San Bernardino, in which the president said the country needed to stay the course on its strategy.

"I swear, I wish he hadn't spoken at all," Rubio said.

The rally, which included an appearance by Rubio's wife Jeannette and introductions by Nevada Lt. Gov. Mark Hutchison and Rick Harrison of the show "Pawn Stars," came a day before a CNN Republican presidential debate at The Venetian Las Vegas hotel-casino.

Most of the candidates are holding public campaign events in Nevada before or after the debate, including Donald Trump and Ted Cruz, who's been on the rise in the polls in early voting Iowa.

"I'm not worried. These campaigns ebb and flow," Rubio told The Associated Press about Cruz's upswing. "We're incredibly confident that if we continue to do what our campaign is doing we're going to do well."