By Andrew Seidman, Trenton Bureau

On the eve of the caucuses that kick off the presidential nominating process, Iowa's popular governor gave New Jersey's Gov. Christie a tacit nod of approval by introducing him to voters here as a "great friend of mine" who had helped the GOP expand its power across the country.

Iowa Gov. Terry Branstad has stayed neutral in the campaign, and he did not explicitly endorse Christie Sunday evening. However, Branstad vouched for the New Jersey governor at a key moment, as many undecided voters prepare to caucus on Monday. Branstad is also scheduled to appear with Christie at a town-hall-style meeting Monday morning.

Also Sunday, Christie's campaign said it had raised about $3 million in the fourth quarter of 2015 and began the year with about $1 million in the bank. Christie's fund-raising lags top candidates like Florida Sen. Marco Rubio, who entered 2016 with more than $10 million on hand.

"We've run the smartest campaign of everybody, a lean, mean campaign," Christie's chief strategist, Mike DuHaime, said after Thursday's debate in Des Moines.

The super PAC supporting Christie's candidacy disclosed Sunday that it had raised $5.1 million in the second half of 2015 and entered the new year with $3.3 million.

Branstad, addressing a crowd of several hundred inside a pub, said Christie's 2009 defeat of incumbent Democratic Gov. Jon Corzine influenced his own decision to run again for governor of Iowa.

Branstad recounted how Christie helped raise money for his 2010 campaign, and for his reelection in 2014, when the New Jersey governor was chairman of the Republican Governors Association.

"He helped us pick up states that nobody thought we could win, like Illinois, Massachusetts, and Maryland," Branstad said.

"He's a great team player, a great personal friend," Branstad said.

Just 3 percent of likely Republican caucus-goers pick Christie as their top choice, according to a Des Moines Register/Bloomberg Politics poll released Saturday.

Celebrity Donald Trump and Texas Sen. Ted Cruz lead the field.

Christie's campaign does not expect to win the state -- he is scheduled to be in New Hampshire on Monday night -- but is betting that Branstad's political operation could help him exceed expectations here.

Christie's Iowa state director was a top aide to Branstad's 2014 campaign, and some of Branstad's top financial backers are also supporting Christie.

Christie on Sunday suggested that if he were president, there might be a job for Branstad in Washington. He also poked fun at Cruz, whom Branstad recently said needed to be defeated because of his opposition to federal ethanol mandates that benefit Iowa farmers.

"Ol' Ted Cruz, Terry Branstad's favorite guy," Christie said to laughter. Referring to Branstad's comments, Christie said, "That's a bad day in Iowa, isn't it?"

He compared the U.S. Senate to grade school: Members are told where to sit and when they have recess, Christie joked. As a governor, he said, "You know your judgments have consequences."

"We cannot make the same mistake again, everybody. Do not send another first-term United States senator," Christie said, referring to Rubio and Cruz. "No matter how good a speech they give ... no matter how pretty they look, it don't matter. We've seen it with Barack Obama."

Rubio has questioned Christie's conservatism, while Cruz has mostly ignored the New Jersey governor.

(c)2016 The Philadelphia Inquirer