Ted Cruz is outspending Marco Rubio by almost 2-to-1 on ads heading into Super Tuesday.
Cruz and his super PAC allies have spent $6.2 million, according to NBC News, which relies on ad tracker SMG Delta. Rubio's team has spent $3.5 million, including about $960,000 in Texas and $690,000 in Virginia.
Donald Trump has spent $1.1 million.
Rubio has consistently been one of the top spenders of the election.
Mack backs Rubio
Former U.S. Sen. Connie Mack joined the Rubio team Monday.
"Marco is the right choice for conservatives, Republicans, Floridians and all Americans who recognize the importance of this historic election and the need to lead our country to a New American Century. Marco has represented the State of Florida well, and he recognizes the time has come for a new generation of conservative leaders to step up and fill a void that has been missing in the White House. I knew Ronald Reagan. I served with Ronald Reagan. And only Marco Rubio can continue the legacy of Ronald Reagan," he wrote in a statement.
Martinez does, too
And another mainstream Republican Party endorsements for Rubio on Monday came from former Florida Sen. Mel Martinez.
Martinez was the first Cuban-American elected to the U.S. Senate, in 2004. He held his seat until 2009; Rubio was elected the following year to fill the post. Like many other recent Rubio Florida backers, Martinez had initially supported former Gov. Jeb Bush for president. He'd hinted that Rubio would be his likely backup.
"Just like Marco's family, this country changed my life and my family's history forever, and the best way to repay the debt I owe America in this election is to help Marco Rubio become our next president," Martinez said in a statement provided by Rubio's campaign. "Our country deserves to have Marco Rubio as our next president, because he will unite us and move us toward the common purpose of making the American Dream a reality for more Americans than ever before."
Return to Miami
Rubio will hold a Florida kickoff rally tonight in Miami.
The event will be held at Ronald Reagan Equestrian Center at Tropical Park and begins at 8.
Will Bush join Rubio?
In Sanders' corner
Democratic U.S. Rep. Alan Grayson, a U.S. Senate candidate who sits on the Hillary Clinton campaign's "Florida Leadership Council," has endorsed Bernie Sanders for president.
Grayson casts himself as the antiestablishment candidate — which is logical because the Democratic establishment sees the populist hedge fund manager as a train wreck — so Sanders is a logical choice.
Grayson based it on online feedback, and announced his decision in a fundraising email.
Adam C. Smith and Patricia Mazzei contributed.