WASHINGTON — Government spending and debt are emerging as a campaign tug-of-war, with Mitt Romney blaming President Barack Obama for a “prairie fire of debt” and Obama calling the charge a “cowpie of distortion.”

What gives? In a word, polling.

The American public is growing increasingly distressed about government spending and high budgets, polls show. The issue now ranks as high on the worry scale as lack of jobs.

And it worked well for Republicans in 2010, who galvanized voters with ads and flyers that drew attention to government red ink and took back control of the U.S. House after four years of Democratic rule.

Republicans are looking for that magic again.

Romney has maintained a drumbeat of criticism over Obama’s handling of federal spending and the national debt in recent weeks, forcing the president on the defensive on an issue where public opinion is stacked against him.

In Iowa this month, Romney said a “prairie fire of debt” was sweeping across the nation, threatening the country’s future. He accused Obama of inflating the debt that he had pledged to reduce and ballooning the federal budget deficit with the 2009 economic stimulus and 2010 health care bill after saying he would cut it sharply.

Obama, in campaign events in Colorado, California and Iowa last week, argued that federal spending had slowed to rates not seen in decades after he inherited a $1 trillion debt and later pushed for $2 trillion in spending cuts.

The president pointed to Romney’s tax proposal, saying it would give millionaires tax cuts at the expense of the debt.

Obama called Romney’s claims a “cowpie of distortion” and would saddle the debt with $5 trillion in new tax cuts, likening it to trying to put out “a prairie fire with some gasoline.”

“What happens is, the Republicans run up the tab, and then we’re sitting there and they’ve left the restaurant,” Obama said at a campaign event in Des Moines. “And then they point and (say), ‘Why did you order all those steaks and martinis?’?”

Obama’s defensive crouch on debt and spending reflect a hard reality: Polls consistently show voters, including sought-after independents, placing more trust in Romney to handle the massive debt.

The nation’s economy remains a focal point for voters, but many remain concerned that years of heavy federal spending on guns and butter could leave the U.S. in a similar position as Greece and other European nations grappling with massive debt.

A Gallup/USA Today poll conducted May 10-13 found that overall, 82 percent of Americans called the “federal budget deficit and debt” extremely or very important, a level of interest comparable to unemployment.

The same poll found Romney with a broad advantage on handling the budget deficit and debt, with 54 percent saying he would do a better job handling it compared with 39 percent who chose Obama.

The results mirrored an April Washington Post/ABC News poll, which found that 51 percent of Americans sided with Romney on handling the federal budget deficit, compared with 38 percent for Obama. Among independents, 60 percent preferred Romney while 29 percent thought Obama would do a better job handling it.

The White House has tried to respond. Press secretary Jay Carney cited an analysis by MarketWatch that said spending under Obama had grown more slowly than any president since Dwight Eisenhower.

A few hours later, Obama picked up on the piece, telling donors in Denver that his work to pay down the federal debt in a “balanced and responsible” way was “starting to appear in places — real liberal outlets like the Wall Street Journal — since I’ve been president, federal spending has risen at the lowest pace in nearly 60 years.”

MarketWatch is published by Dow Jones & Co., which also publishes the Wall Street Journal.

Yet Obama’s budget stewardship is open to interpretation. The debt now stands at $15.7 trillion, compared to $10.6 trillion on his inauguration day. On a dollar basis, that’s the biggest ever jump in the debt.

How much the debt has grown can also be measures as a percentage of what he inherited. By that measure, the debt has increased by half during the 31/2-year Obama administration.

During President Ronald Reagan’s eight-year administration, the debt nearly tripled, from about $910 billion to more than $2.6 trillion.