By David Espo
Associated Press

WEST PALM BEACH, Fla. — On a day that combined two campaigns into one, President Barack Obama on Wednesday challenged Republicans to raise taxes on the rich as GOP rivals Mitt Romney and Newt Gingrich swiped at him on the economy and criticized each other over immigration.

With a week to go before the Jan. 31 Florida Republican presidential primary, the polls suggested a tight race, although Romney and his allies seized a staggering advantage in the television ad wars.

They have reported spending $14 million combined on commercials, many of them critical of Gingrich, and a total at least seven times bigger that the investment made by the former House speaker and an organization supporting him.

Obama’s political timeline was a different one, Election Day on Nov. 6.

In a campaign-style appearance in Iowa, he demanded Congress approve a tax increase for anyone like Romney whose income exceeds $1 million a year.

“If you make more than a million dollars a year, you should pay a tax rate of at least 30 percent. If, on the other hand, you make less than $250,000, which includes 98 percent of you, your taxes shouldn’t go up,” he said after touring a manufacturing plant in Cedar Rapids and in a state that he won in 2008 that was expected to be a battleground in the fall.

“This is not class warfare,” he said. “That’s common sense.”

As Obama surely knew, it was an offer Gingrich, Romney and the anti-tax Republicans in Congress are likely to find easy to refuse.

Referring to Obama’s call in the speech for Congress to end tax breaks that encourage companies to ship jobs overseas, Romney said he didn’t know of any.

Instead, he said the president presides over “the most anti-business, anti-investment, anti-job creator administration I’ve ever seen, and so, what I’ll do — I’ll get America to work again. I spent 25 years in business.”

Gingrich was far harsher at an appearance in Miami.

“If he actually meant what he said it would be a disaster of the first order,” Gingrich said of the president’s call for higher taxes on millionaires.

The former House speaker said the president’s proposal would double the capital gains tax and “lead to a dramatic decline in the stock market, which would affect every pension fund in the United States.”

“It would affect every person who has a 401(k). It would attack the creation of jobs and drive capital outside of the United States. It would force people to invest overseas. It would be the most anti-jobs single step he could take,” he said.

Under current law, investment income is taxed as the rate of 15 percent, a fact that has come to the fore of the campaign in recent days with the release of Romney’s income tax return.

Wages, by contrast, are taxed at rates that can exceed 30 percent.

Electability is the top concern for GOP primary voters, according to polls taken in the early primary and caucus states, so both Republicans were eager to paint a contrast with the president.

But Romney and Gingrich also focused on the Florida primary now seven days distant.

Romney has long led in the state’s polls, but Gingrich’s upset victory last Saturday in the first-in-the-South primary in South Carolina revitalized his candidacy and raised questions about the former Massachusetts governor’s staying power.

Former Pennsylvania Sen. Rick Santorum is also on the ballot, as is Texas Rep. Ron Paul.

But Santorum has been sinking in the polls as Gingrich rises, and Paul has indicated he intends to bypass the state to concentrate on caucuses to be held elsewhere.

That gives Florida the feel of a two-man race, and Romney and Gingrich are treating it that way.

The two men sparred heatedly Monday night in a debate that virtually relegated Santorum and Paul to supporting roles.

A second debate is set for Thursday in Jacksonville.

And if their separate appearances during the day on the Spanish-language television network Univision is a guide, it will be as feisty as the first.

Gingrich referred acidly to Romney describing a policy of “self-deportation” as a way of having illegal immigrants leave the country without a massive roundup.

“You have to live in a world of Swiss bank accounts and Cayman Island accounts and automatically $20 million income for no work to have some fantasy this far from reality,” he said, referring to some of the details disclosed this week when the former Massachusetts governor released his tax returns.

“For Romney to believe that somebody’s grandmother is going to be so cut off that she is going to self-deport, I mean, this is an Obama-level fantasy.”

Romney’s campaign swiftly produced evidence that aides to Gingrich had used the term “self-deport” approvingly, and the former governor attacked.

“I recognize that it’s very tempting to come out to an audience like this and pander to the audience,” Romney said. “I think that was a mistake on his (Gingrich’s) part.”

Gingrich also ran into trouble over a radio ad his campaign was airing that called Romney “anti-immigrant.”

Sen. Marco Rubio, R-Fla., who is neutral in the presidential race, criticized the commercial, and Romney said the term “anti-immigrant” was an epithet.

Gingrich made a stop in Cocoa, center of the state’s now-withered space industry, and he cheered his audience by envisioning construction of the first permanent base on the moon.

He also promised a “robust industry” of “commercial near-earth activities” to include science, tourism and manufacturing.

He said he hopes to stimulate investment by having the government offer prizes to private companies, but he did not elaborate.

For Obama, Iowa was the first of five stops in three days following a State of the Union speech in which he stressed the theme of income equality that is expected to be one of the cornerstones of his re-election campaign.

He also wove in proposals to help restore the U.S. manufacturing base that has withered in the course of the recession that began in 2008.

“Our economy is getting stronger, and we’ve come too far to turn back now,” he told workers and guests at a conveyor manufacturing plant in Cedar Rapids.

Speaking of Republicans, he said, “Their philosophy is simple: We’re better off when everyone is left to fend for themselves and play by their own rules.”

It’s a message that may be received differently depending on the local economy.

Iowa’s unemployment was most recently measured at 5.6 percent, well below the national average.

In Arizona, which has its primary in four weeks, joblessness is 8.7 percent, while Nevada’s at 12.6, the highest in the country. Its caucuses are Feb. 4.