(CNN) -- Mitt Romney and Paul Ryan hit the campaign trail Thursday to pitch energy policy and defense spending, as new polls showed President Barack Obama maintaining a slight lead in three key swing states after Romney named the conservative House Budget Committee chairman as his running mate. Four days ahead of the Republican National Convention, certain presidential nominee Romney sought to build momentum with a continued focus on his economic policies mixed with attacks on Obama's handling of a stalling recovery. However, the controversy this week over Republican Rep. Todd Akin's incendiary remarks on "legitimate" rape and pregnancy has dominated the political chatter and raised questions about whether the conservative Christian from suburban St. Louis can unseat vulnerable Democratic Sen. Claire McCaskill in Missouri.
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NEW: Romney calls for more oil drilling, less regulation
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Mitt Romney and Paul Ryan hit the campaign trail on Thursday
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New polls show President Obama maintaining a slight edge in three key states
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GOP officials say a possible hurricane won't derail Romney's nomination next week in Tampa
@placeholder has said he would not support extending the federal subsidy for wind power, which expires at the end of the year.
"Under a @placeholder administration, this will not happen," Ryan said of the automatic cuts to military spending.