Others are appealing directly to the Democrats. Sen. Gordon H. Smith (R-Ore.) responded to a recent attack ad by associating himself with likely Democratic presidential nominee Obama.
"Who says Gordon Smith helped lead the fight for better gas mileage and a cleaner environment?" says a Smith ad. "Barack Obama."
That ad has sparked controversy because Obama has endorsed Smith's Democratic opponent, Jeff Merkley.
Other Republicans are fighting back, portraying their support for the industry as important to the economy and national security.
Punishing the industry would only increase U.S. dependence on foreign oil by discouraging domestic production, they say.
And still others unabashedly defend industry involvement in national politics.
"At a time when we're facing $4 gasoline, I think that you need people who've been in the energy industry to tell us what to do," said Steve Pearce, a House member from New Mexico who is running for the Senate.
Dick Wadhams, campaign manager for Colorado Senate candidate Schaffer, said that Democrats' attacks on the oil industry could backfire against growing public support for expanded domestic energy exploration.
And Freedom's Watch has run ads attacking Democrats for blocking expansion of domestic energy production.
"Chris Carney voted five times against environmentally safe domestic energy production -- voted against American energy independence," says a radio ad scheduled to run in the Pennsylvania Democrat's House district. "But Chris Carney stands in the way while we cut back on gas and groceries, family outings and summer vacations."
The Democrats, in a broad, cross-country assault, are aiming at House and Senate Republicans for ties to oil and to President Bush.
Former New Hampshire Gov. Jeanne Shaheen, the Democratic challenger to Sen. John E. Sununu (R-N.H.), filmed a TV ad at what has become Democrats' favorite campaign stop: a filling station.
The Democratic Senatorial Campaign Committee has posted ads attacking Republicans -- including Oregon's Smith -- for ties to the oil industry on a website used by consumers to check on gas prices.
The House Democrats' campaign committee aired radio ads featuring a Bush impersonator who "thanks" 13 Republican representatives for supporting the industry's energy agenda.
"Sure, gasoline is over four bucks a gallon and the oil companies are making record profits, but what's good for Big Oil is good for America, right?" the ad goes. "I guess that's why they call us the Grand OIL Party."
