Bentonville, Arkansas (CNN) After weeks of savaging Texas Sen. Ted Cruz , Republican front-runner Donald Trump is firmly setting his sights on another GOP rival.

In his furthest-reaching attack yet, Trump on Saturday accused Florida Sen. Marco Rubio of stealing from the Florida Republican Party and suggested Rubio should have been "indicted" for using a state party American Express card for personal expenses.

"Rubio stole from the Republican Party," Trump said of Rubio, with whom he has recently engaged in a public war of words . "But you know what happened? They said, 'You stole from the party.' He says, 'No, I didn't.' 'Yes, you did, you had a driveway bill,' 'No, I didn't,' 'Yes, you did,' 'Oh, OK, well, uh,' he reimbursed them."

Rubio speaks to an aide on Capitol Hill as he arrives for the weekly Senate Republican Policy Committee luncheon in September 2013.

Rubio speaks to an aide on Capitol Hill as he arrives for the weekly Senate Republican Policy Committee luncheon in September 2013.

Rubio returns to the Capitol after meeting with Obama and other Republican leaders about the government shutdown in October 2013.

Rubio returns to the Capitol after meeting with Obama and other Republican leaders about the government shutdown in October 2013.

Rubio, center, speaks to members of the media as Sen. Ron Johnson, left, and Rep. Ron DeSantis listen during a news conference on Capitol Hill in October 2013.

Rubio, center, speaks to members of the media as Sen. Ron Johnson, left, and Rep. Ron DeSantis listen during a news conference on Capitol Hill in October 2013.

Rubio confers with McCain as U.S. Ambassador to Syria Robert Ford testifies before the Senate Foreign Relations Committee in October 2013.

Rubio confers with McCain as U.S. Ambassador to Syria Robert Ford testifies before the Senate Foreign Relations Committee in October 2013.

Rubio speaks in November 2013 during a campaign stop for Virginia Attorney General Ken Cuccinelli, the Republican candidate for governor of Virginia.

Rubio speaks in November 2013 during a campaign stop for Virginia Attorney General Ken Cuccinelli, the Republican candidate for governor of Virginia.

Rubio addresses an event held by the American Enterprise Institute for Public Policy Research in January 2014.

Rubio addresses an event held by the American Enterprise Institute for Public Policy Research in January 2014.

From left, Sens. Cory Booker, Rubio, Kristen Gillibrand and John McCain wait for Obama to deliver the State of the Union address in January 2014.

From left, Sens. Cory Booker, Rubio, Kristen Gillibrand and John McCain wait for Obama to deliver the State of the Union address in January 2014.

Rubio, left, and Florida Gov. Rick Scott speak to the media in Doral in February 2014.

Rubio, left, and Florida Gov. Rick Scott speak to the media in Doral in February 2014.

Rubio, left, is greeted as he arrives at a restaurant in Doral in February 2014.

Rubio, left, is greeted as he arrives at a restaurant in Doral in February 2014.

Rubio checks his phone in March as he arrives for a Capitol Hill news conference to introduce a proposal for an overhaul of the tax code.

Rubio checks his phone in March as he arrives for a Capitol Hill news conference to introduce a proposal for an overhaul of the tax code.

Rubio speaks to the media at the Doral restaurant in April 2014.

Rubio speaks to the media at the Doral restaurant in April 2014.

Rubio speaks to the media in front of a wall dedicated to the victims of the violence in Venezuela as he shows support for the Venezuelan community at a restaurant in Doral, Florida, in April 2014.

Rubio speaks to the media in front of a wall dedicated to the victims of the violence in Venezuela as he shows support for the Venezuelan community at a restaurant in Doral, Florida, in April 2014.

Rubio talks to aides in December before speaking on President Barack Obama's announcement about revising policies on U.S.-Cuba relations.

Rubio talks to aides in December before speaking on President Barack Obama's announcement about revising policies on U.S.-Cuba relations.

Rubio speaks with the media after delivering remarks during the graduation of small business owners from the Goldman Sachs 10,000 Small Businesses program held in Miami in February.

Rubio speaks with the media after delivering remarks during the graduation of small business owners from the Goldman Sachs 10,000 Small Businesses program held in Miami in February.

Rubio, center, arrives in the House chamber ahead of Israeli Prime Minister Benjamin Netanyahu's address to a joint meeting of the U.S. Congress in March.

Rubio, center, arrives in the House chamber ahead of Israeli Prime Minister Benjamin Netanyahu's address to a joint meeting of the U.S. Congress in March.

Sen. Mike Lee, left, and Rubio talk before a news conference to introduce their proposal for an overhaul of the tax code in March.

Sen. Mike Lee, left, and Rubio talk before a news conference to introduce their proposal for an overhaul of the tax code in March.

Florida Sen. Marco Rubio speaks in October 2013 at the Values Voter Summit, held by the Family Research Council in Washington.

Florida Sen. Marco Rubio speaks in October 2013 at the Values Voter Summit, held by the Family Research Council in Washington.

Rubio used a corporate American Express card that the Florida state GOP entrusted to him during his time as a Florida state lawmaker for thousands of dollars in personal expenses, which he later reimbursed.

In November, Rubio released nearly two years of statements for the card , hoping to put to rest any lingering questions of impropriety.

Trump suggested on Saturday that Rubio only reimbursed the funds after he was caught.

"For some reason, he didn't get indicted. Why didn't he get indicted?" Trump asked.

And then Trump pointed to New Jersey Gov. Chris Christie , a former U.S. attorney, who endorsed Trump on Friday and joined him for Saturday's rally at an airport hangar here.

"Chris Christie would've indicted him so fast," Trump said.

Joe Pounder, a spokesman for Rubio, dismissed Trump's allegations in a statement to CNN.

"Donald Trump is nothing but a con man who will say anything to defraud the American people like he did at Trump University, taking four businesses into bankruptcy or hiring foreign workers over Americans," Pounder said. "The crowd at Trump's event wasn't applauding and the American people aren't either."

Trump, Christie take aim at Rubio

Trump's latest attack was one of dozens he and Christie leveled against Rubio in back-to-back remarks here on Saturday. Christie, who quit the race after faltering in the New Hampshire primary and after a debate in which he took a no-holds-barred approach to attacking Rubio, endorsed Trump on Friday in a news conference that stunned the political world.

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Trump and Rubio until recently enjoyed a relative détente, as Rubio avoided leveling any direct attacks against Trump until Thursday's CNN Republican debate and Trump previously only offering occasional references to Rubio's sweatiness.

But as establishment Republicans grapple with a creeping sense that Trump's nomination is nearing inevitability and with donors fretting over Rubio's failure to notch a single primary win, Rubio pounced.

Along with Cruz, who ended his détente with Trump ahead of the Iowa caucuses , Rubio lashed into Trump at the debate, accusing him of defrauding working-class Americans and concluding that "the time for games is over."

Rubio hasn't stopped since, slamming Trump as a "con artist" and also matching the personal nature of Trump's attacks, saying Saturday, "Donald Trump likes to sue people. He should sue whoever did that to his face."

Rallying several thousand in an airport hangar here Saturday, attacks against Rubio rolled off of Trump's tongue: "lightweight Rubio," who has a "little mouth on him," Trump said, is actually a "worse" liar than Cruz, Trump declared. Trump had previously branded Cruz as the "single biggest liar" he had ever met.

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But before Trump launched into his attack on Rubio's "really large ears" and the Floridian's alleged profuse sweating -- "I have never seen a human being sweat like he sweats," Trump said -- Trump let his new Rubio attack dog, Christie, level a few attacks of his own.

Known for his equally brash style, the New Jersey governor focused his attacks on Rubio's attendance record in the Senate, alleging that Rubio has missed a majority of meetings for the committees on which he sits.

"Hey Marco, show up for work for the American people," Christie said, echoing an attack Trump leveled at Rubio on Friday, when Trump said Rubio "defrauded Florida" by getting elected to the Senate and then failing to show up for votes.

Rubio has been consistently criticized for his voting attendance record in the Senate, which last year was among the worst of any sitting senator.

Christie wasn't just an attack dog, though, also defending Trump from Rubio's suggestion that Trump has only been successful because he inherited millions of dollars from his father.

Trump received a $1 million loan from his father early in his career and later inherited a share of his father's more than $200 million net worth, by which time Trump had already done much to build up his own fortune.

Christie called the $1 million loan "a very small bit of help" and Trump on Saturday would later describe the loan as "a tiny amount of money," prompting chuckles from the audience.

Pointing to Trump's father's help, Christie said Trump's family "is no different" from others.

Christie also hammered home an issue Trump raised in the last GOP debate -- that Trump is the only candidate to have created hundreds of thousands of jobs -- and took yet another chance to swipe at Rubio.

"Marco Rubio says that he's going to help create jobs. The only person in this race that's created jobs is standing right there. And his name's Donald Trump," Christie said.