MAUMEE, Ohio (Reuters) - President Barack Obama took a shot at China and Republican rival Mitt Romney on Thursday, complaining to the World Trade Organization that Beijing is abusing trade laws by imposing more than $3 billion in duties on U.S. automobile exports.
"Americans aren't afraid to compete," Obama told an enthusiastic crowd in this northern Ohio city hours after his administration filed the complaint with the WTO.
"As long as we're competing on a fair playing field instead of an unfair playing field, we're going to do just fine. We're going to make sure that competition is fair."
The Democratic president's speech kicked off a two-day campaign bus tour aimed largely at blue-collar workers in Pennsylvania and Ohio, crucial battleground states in the November 6 presidential election.
The complaint to the WTO seemed directed particularly at Ohio, home to thousands of auto-supply workers, many of whom have jobs likely saved by the U.S. government's $80 billion bailout of the industry Obama supported and Romney opposed.
It was also a counterpunch to Romney's claims that Obama has not been tough enough on China's trade policies, and gave Obama's campaign another way to remind voters of its efforts to tie Romney's work as a private equity executive to the outsourcing of American jobs to China.
The WTO in Geneva confirmed it had received the complaint from the United States, the nation's third such challenge to China following action against duties imposed by Beijing on the exports of certain U.S. steel and chicken products.
The president's bus trip - his first of the 2012 presidential campaign - included stops in the Toledo area, where auto plants have been affected by the Chinese duties.
The trade duties cover more than 80 percent of U.S. auto exports to China, including cars manufactured in Toledo and Marysville, Ohio, and Detroit and Lansing, Michigan.
Beijing slapped anti-dumping and countervailing duties on U.S. auto exports in December 2011 on roughly 92,000 autos and SUVs, worth $3.3 billion in annual U.S. exports.
"The duties disproportionately fall on General Motors (GM.N) and Chrysler products precisely because of the actions that President Obama took to support the U.S. auto industry during the financial crisis," an administration official said.
U.S. automakers typically are reluctant to comment on U.S.-China trade conflicts, wary of offending officials who represent the fast-growing Chinese market.
Scott Paul, executive director of the Alliance for American Manufacturing, a group that promotes U.S. manufacturing and products, praised Obama's move.
"American workers and manufacturers strongly support President Obama's decision to launch a trade enforcement action against China's unfair auto tariffs," Paul said.
"The deck in China is stacked against American automakers and workers, and this case will help to level the playing field. Less than 1 percent of the estimated 18 million vehicles sold in China last year were made in America, despite the fact that the Detroit Three brands are growing more popular every day."
Romney's campaign, as expected, took a more skeptical view, casting the president's move as one of political convenience.
"President Obama's election-year conversion on China is just the latest in a long string of disappointments and broken promises," said Lanhee Chen, Romney's campaign policy director.
"The American people are looking for a leader who will stand up to China and demand that they play by the rules, not one who will carefully time his actions to coincide with bus tours through swing states in the last months of his term," Chen said.
Buoyed by the Supreme Court's declaration that the president's healthcare overhaul is constitutional but anxious about shaky economic data, Obama's campaign is targeting blue-collar workers who have been hit hard by the loss of manufacturing jobs.
Knocking China is likely to appeal to that group.
Obama's trip comes against a backdrop of mixed poll numbers, fundraising challenges and European threats to the U.S. economy that could derail Obama's hopes for re-election.
A report on Friday is expected to show the U.S. unemployment rate held at a high 8.2 percent in June, although data on Thursday offered some hopeful signs for the labor market, including a drop in claims for jobless benefits and a pickup in private-sector hiring.
An average of polls by RealClearPolitics shows the president ahead of Romney by a tight 2.6 percentage points in Ohio and nationwide.
Obama is polling particularly well with women and Hispanics, but working-class men are up for grabs.
Such voters are among the key targets for the Obama campaign's emphasis on Romney's work at Bain Capital, the private equity firm the Republican once led. Bain invested in companies that were early adopters of outsourcing business activities to cheap labor markets such as China.
At a rally in this suburb of Toledo, Obama - in short sleeves and speaking against a backdrop of hay bales - took a swipe at Romney's business record, saying the Republican's experience has been in owning companies that were called "pioneers of outsourcing."
Afterward, on the way to his next campaign event, the president stopped at a diner to have a cheeseburger and at a farmer's market to buy some corn.
"It's a race for blue-collar men," said Democratic strategist Bud Jackson, noting that such voters have been particularly affected by the sluggish economy.
"The ability of the president to win over blue-collar men is more tied to the reality of the moment: Are jobs being created and do people feel more optimistic? For him, the proof is somewhat in the pudding."
Ohio Senator Rob Portman, a Republican who is seen as a potential vice presidential pick for Romney, said Obama's record at bringing down unemployment was shoddy.
"Unfortunately, the president overpromised and under delivered. Unemployment remains above 8 percent, and it has been at that level for more than three years - the longest stretch since the Great Depression," Portman wrote in an opinion piece in the Cleveland Plain Dealer, an Ohio newspaper.
"To get the economy back on track, we can't continue with the status quo. Bigger government, more regulations, higher taxes, record federal spending and massive borrowing haven't worked."
Ohio's unemployment rate is below the national average, falling to 7.3 percent in May, and the Obama campaign notes that it has fallen 3 percentage points since Obama took office.
Part of that drop is thanks to Obama's bailout of the automobile industry, the campaign argues, resulting in investment from U.S. automakers in the greater Toledo area.
Additional reporting by Alister Bull, Matt Spetalnick and Ben Klayman' editing by David Lindsey, Doina Chiacu and Todd Eastham