Manuel Balce Ceneta/AP Photo

Ron Paul may have little chance of capturing the GOP presidential nomination, but that hasn’t stopped his political opponents from going after a tax plan he recently introduced that would slice $1 trillion from the federal budget.

Newt Gingrich, the former House speaker and Paul’s 2012 Republican rival, labeled the plan “a non-starter.”

“If you come to me and tell me I need to lose 30 pounds and you’re going to amputate my right leg, I think it’s a non-starter, ” Gingrich told the Quad City Times.

Herman Cain, the latest Republican presidential candidate to see a surge in the polls, hinted that Paul’s drastic approach to budget cutting won’t work.

“If you listen to his positions on a lot of things, it’s always, ‘Let’s throw out the baby with the bathwater,’” Cain told CNN.

Paul’s campaign staff argues that the attacks from established candidates reinforce the idea that Paul is having a greater impact on the race by raising fiscal issues the others won’t touch.

And his tax plan is getting support from some of the loudest voices in the GOP.

Talk show host and conservative political commentator Rush Limbaugh told his listeners that genuine, big spending cuts are the only things that are going to bring the U.S. economy back into balance.

“But nobody on our side’s ever really seriously proposed it, and Ron Paul’s going to,” said Limbaugh.

Paul’s economic plan involves $1 trillion in spending cuts, the bulk coming from the elimination of five Cabinet-level departments, including Energy, Interior, Housing and Urban Development, Commerce and Education.

Paul would wring out additional savings by eliminating all foreign aid and wars, and dialing back spending to 2006 levels.

In the latest ABC News poll, only 8 percent of likely Republican voters mentioned Paul as best to handle the economy — compared with Romney and Perry, who both topped the poll at 22 percent.

At a recent campaign stop in New Hampshire, ABC News asked Paul what he planned to do to change those numbers.

“I’m not changing a thing,” said Paul.