MIAMI - President Obama visited a tunnel project at the major port here on Friday to promote a new plan to rebuild the nation's roads, bridges and points of commerce - a series of measures that White House officials argue could appeal to business-minded Republicans.

In a brief visit, Obama said hiring construction workers for "infrastructure" projects would help lower the nation's high unemployment rate - no industry has been harder hit than construction - and make the country more competitive in the long run. The proposals range from $4 billion to invest in rebuilding roads and bridges to tax breaks designed to attract investors, at home and abroad, to construction projects.

"There are few more important things we can do to create jobs right now and strengthen our economy over the long haul by rebuilding our infrastructure that powers our businesses and our economy," Obama said, surrounded by blue shipping containers. "This should not be a partisan idea."

Obama's trip here was designed to show that he is fighting to accomplish second-term priorities despite significant barriers and a polarized political climate that makes the passage of ideas with bipartisan support difficult.

While members of both parties have historically backed proposals to increase spending on roads and bridges, Republicans are raising objections to the tax increases that would probably be necessary to help pay for fresh spending.

The White House says the proposals would require $21 billion in taxpayer dollars, money it has to offset to meet its promise that they won't add to the deficit. Obama has also proposed $40 billion in immediate federal spending on thousands of projects that are in need of prompt repairs - a proposal called "Fix It First."

Specific details will be laid out in Obama's 2014 budget that will be released April 10.

"Last time, I think he wanted to tax the same people that were supposed to create the job," Don Stewart, a spokesman for Senate Majority Leader Mitch McConnell, R-Ky., said Friday.

Writing in The Miami Herald, Sen. Marco Rubio, R-Fla., said Obama needs to listen to people in Florida "to get a true sense of the effect more tax increases and spending hikes will have on our nation's middle class."

Because of the political paralysis, the opposite of what Obama is advocating is happening now. Deep cuts to federal spending known as sequestration are slicing $4 billion out of federal construction projects this year, according to the Associated General Contractors of America.

Obama would spend $4 billion on local and state infrastructure projects. He would invest $10 billion in an "infrastructure bank" that would make loans to private companies.