PITTSBURGH - Karl Rove, the Republican operative and former senior adviser to President George W. Bush, said Wednesday at an appreciative Marcellus Shale natural gas conference that the sweeping Republican victory Tuesday would put an end to most of the industry's legislative threats.

Rove said a new Republican House of Representatives supportive of the energy industry "sure as heck" would not pass climate-change legislation that the outgoing Democratic Congress had been unable to pass.

"Climate is gone," said Rove, the keynote speaker on the opening day of a two-day shale-gas conference sponsored by Hart Energy Publishing L.L.P. And Rove told the trade show, "I don't think you need to worry" the new Congress will consider proposed legislation to put the controversial practice of hydraulic fracturing under federal rather than state regulation. The procedure, known as "fracking," is responsible for the dramatic growth of shale-gas drilling in formations such as Pennsylvania's vast Marcellus Shale.

"I think we're back to a period of sensible regulation," said Rove, a commentator on Fox News and in the Wall Street Journal.

While Rove spoke, several hundred colorfully dressed anti-drilling activists protested outside the David L. Lawrence Convention Center in Pittsburgh, but their drumbeats could not be heard inside the conference as about 2,000 people dined on steak and potatoes, then heard Rove's analysis of Tuesday's election.

Rove basked in the magnitude of the GOP election victory, which he said was a repudiation of Obama's legislative record. He also said it reflected a change in Obama's attitude that contrasted with the "optimistic and uplifting inspirational tone" when he came into office.

"This man cannot try to pass a major piece of legislation without demonizing some group of people and making them a target," said Rove, citing Obama's targeting of the health insurance industry, Wall Street bankers, and energy companies to advance his agenda.

"He had a unique moment to turn the page and usher in a new era, but it didn't happen," he said.

Rove said Obama could follow one of two models in the wake of the Democratic defeat - the conciliatory approach of Bill Clinton after his 1994 midterm setbacks, or the attack mode of Harry Truman, who relentlessly assailed the "do-nothing" Congress ahead of the 1948 election.

Rove said it would be difficult for Obama to take a combative tone because his party still controls the Senate. Rove said he also believed that the new Republican House "isn't going to give him a lot of targets - they're going to be positive and optimistic and move an agenda."

"It's going to be interesting to see where he comes down," he said.

Rove said the Republicans' control of a majority of state legislative bodies - 19 of 99 state legislative houses switched to the GOP on Tuesday, including the Pennsylvania House - would ensure that the party would expand its control in Washington through forthcoming congressional redistricting. The GOP's success in statehouse races gives the party much more command over setting new district lines for the next decade.

"Why does this matter?" Rove said. "Because he who controls the pen draws the line, and he who draws the line decides the outcome of most contests."

Rove said he had "no idea" who would emerge as the front-runner among many potential Republican presidential aspirants for 2012, but he said the next year would be critical for candidates to write a "compelling narrative" differentiating themselves from Obama, explaining the vision and creating the sense by the end of next year that they have the leadership to unite the Republican Party.

"I think Republicans are going to be hungry to beat Obama, and they're going to want somebody who can unite the party and do that," he said.

Rove lavished praise on the gas-drillers, who he said were bringing prosperity to parts of Pennsylvania.

The political operative said even though Bush failed to win the state in two elections, he likes Pennsylvania very much, except for Southeastern Pennsylvania, which tends to vote Democratic.

"It's a great state. Particularly the people you find in the western part and the central part of the state are really good, decent people," he said. "Philadelphia's a little odd, but you know - now I'll never be able to go back to Philadelphia again.

"But it's a great state."