The Republican National Committee is launching $3 million in independent expenditure television ads in four states, focusing on the energy issue.

The ad is slated to run on network and cable television in Michigan, Ohio, Wisconsin and Pennsylvania and will highlight the differences between Sens. Barack Obama (D-Ill.) and John McCain (R-Ariz.) on energy security.

“Following Barack Obama’s decision to become the only major party presidential candidate in history to not adhere to campaign spending caps, the Republican National Committee has begun an independent expenditure campaign in accordance with FEC regulations,” RNC I.E. consultant Brad Todd said in a statement. Todd’s firm, On Message Inc., produced the ad, which will run from this weekend through July 15.

Todd said the energy issue is “emerging as a defining difference in the race for president.”

The ad buy demonstrates some of the RNC’s financial muscle, relative to its counterpart. Through May 31, the RNC had $53.5 million on hand, compared to almost $4 million for the Democratic National Committee.