(CNN) - Sen. Rob Portman of Ohio on Sunday defended Mitt Romney's ad campaign attacking President Barack Obama over plans for GM and Chrysler to expand production overseas.
"The fact is that we now make Jeeps here in Toledo, Ohio, that we're proud to send to China, to Asia; we export about 25 percent of what we make here, and so if they're going to start production facilities overseas, obviously we're going to lose some of our exports here," Portman said on CNN's "State of the Union."
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He continued: "So that's - that's all the ad says."
Production plans by GM and Chrysler carry weighted political significance around the issue of manufacturing and jobs because of the industry's heavy presence in Ohio and throughout the battleground Midwest.
The Obama campaign strongly underscores the president's decision to accelerate the taxpayer bailout of both companies early in his presidency, a move he and other supporters say saved or created thousands of jobs and positioned those businesses to be successful when sales rebounded.
While enjoying a resurgence at home since, the U.S. auto industry has sought to boost its business in China's fast-growing auto sector. Growing business in Asia has become even more important to American auto manufacturers, considering the industry's woes in economically hard-hit Europe.
Republicans have also branded Obama weak on China over trade.
Recent television and radio ads in Ohio claim GM plans to double the number of cars built there and that Chrysler plans to start making Jeeps – its iconic brand - in China as well.
"Under President Obama, GM cut 15,000 American jobs, but they are planning to double the number of cars built in China which means 15,000 more jobs for China," the radio ad states. "And now comes word that Chrysler is starting to build cars in, you guessed it, China."
The ad concludes arguing that Romney "will stand up for the auto industry. In Ohio, not China."
The commercials sparked sharp rebuke from executives at both automakers, who argued the expansion would not affect American jobs - as noted in the original Bloomberg report that served as the source of Romney's ads.
Obama also responded this week, describing the spots as scare tactics in a last-minute push for Ohio votes.
"You don't scare hard working Americans just to scare up some votes," Obama said Friday to a crowd in Hilliard, Ohio. "That's not what being president is all about, that's not leadership."
As a result of Romney's recent ad, Obama said employees at Jeep are calling their bosses, worried their jobs will be shipped overseas, a claim in the ad that "everybody knows is not true."
"The car companies themselves have told Governor Romney to knock it off," he added.
The ad was rated "Pants on Fire" by the independent, fact-checking group PolitiFact.com. And former President Bill Clinton and Vice President Joe Biden this week tag teamed in their attacks against Romney over the ad.
But Portman on Sunday said the spots were not wrong on accuracy.
"Jeep has said they're going to reopen a facility that was closed after DaimlerChrysler, you know, broke apart years ago and it'll be in China to produce for the Chinese market and that's all the ad says. So there's nothing inaccurate about it," he told CNN Chief Political Correspondent Candy Crowley.
He also argued Romney has the edge in Ohio and sounded confident about winning the state, a battleground viewed by many political observers as the must-win for the presidential election.
No Republican has ever won the White House without carrying the Buckeye State.
"I think we're going to win Ohio. I really do," he said.
– CNN White House Producer Gabriella Schwarz contributed to this report.