Rep. Joe Barton (R-Texas) knows he’s outnumbered. He knows the Democrats on the House Energy and Commerce Committee, where he serves as ranking member, have the ability to “slam things through” when they want to.

But Barton, a 26-year veteran of Congress, has found a way to be effective despite his party’s 36-23 deficit on the committee and the presence of a new liberal chairman, Rep. Henry Waxman (D-Calif.): by leading a unified opposition and throwing rhetorical grenades at some of the Democrats’ top priorities of the past year, such as health care reform and climate change legislation.

“They almost always had us outvoted,” Barton conceded in an interview last week. “But they never had us outgunned intellectually on the substance of the issues.”

Barton is quick to single out the ranking members on key Energy and Commerce subcommittees, such as Rep. Nathan Deal (Ga.) on Health and Rep. Fred Upton (Mich.) on Energy and Environment, for their roles in developing GOP strategy for fighting health care reform and cap-and-trade.

“I think the Republicans have done a pretty good job on the committee of helping frame the issues, pointing out the problems with the thrust of what’s wrong with the Democrats’ domestic agenda,” Barton said.

Another Republican on the panel, Rep. Michael Burgess (Texas), says much of the credit must go to Barton for keeping every GOP Member in the loop and engaged in strategy on the most high-profile battles.

“It’s no accident that the committee’s Republicans stayed together on these things,” Burgess said. “I think Joe’s done a good job of keeping us informed.”

Barton, 60, has been a mainstay on the committee since his second term. He was chairman from early 2004 until Democrats took control of the House at the beginning of 2007, and he has been ranking member ever since. His perch there dovetails nicely with his own priorities and those of his district, which is sandwiched between Dallas and Fort Worth and then dips south into more rural areas. Barton was an engineering consultant in the energy industry and was also a White House fellow at the Energy Department during the Reagan administration before his election in 1984.

“He’s really an ally for the oil and gas industry,” said Joel Noyes, government relations and industry affairs director at the Independent Petroleum Association of America. “He’s one of the very few Members who doesn’t need an education on our issues going in.”

Harvey Kronberg, the publisher of the Quorum Report, a political news service in Texas, said Barton’s value to the state — particularly to its top industries — has increased as senior members of the delegation have left Congress.

“This is probably the weakest delegation we’ve ever had,” Kronberg said. “So there’s some thought that Barton needs to be protected. There’s a ‘circle the wagons’ sense among the business community around senior incumbents.”

But while he’s a hard-line conservative on most issues, Barton can’t afford to be parochial or inflexibly partisan. Energy and Commerce has the broadest portfolio in the House, covering everything from energy and foreign commerce to public health, technology, communications, consumer protection and tourism. So Barton was a major player in the push to get TV broadcasters to switch from analog to digital transmission. He has co-authored legislation through the years concerning the governance of the Food and Drug Administration and its policies on pharmaceutical drugs. And he’s gained some publicity lately — and bipartisan support — for his efforts to change the way college football awards its national championship.

When George W. Bush was in the White House and Republicans still controlled Congress, Barton helped push the administration’s energy policy overhaul through the House in 2005. Burgess, recalling a four-hour debate over ceiling fan standards, said that in contrast to some of the debates on energy since the Democrats have taken control, Barton allowed unlimited Member input in the committee.

“It was pure Athenian democracy,” Burgess said. “Everybody got to speak their mind.”

Still, perhaps Barton’s greatest value to the GOP has been as an acerbic critic of high-profile Democratic priorities such as cap-and-trade and health care reform. Of cap-and-trade, he said last year, “A money machine posing as planetary salvation may help the rookie White House staff write their first budget, but it seems unlikely to stop global warming and sure to impoverish Americans.” Before a White House summit on health care a year ago, he said: “Not all of the Democrats’ ideas are objectionable. Just nearly all.”

Reflecting on the debates of the past year, Barton said there was simply no way committee Republicans were going to swallow cap-and-trade. (A rueful Waxman said he regretted that Barton didn’t believe in the science of climate change “and therefore didn’t see the need for legislation that would have such a dramatic impact on the economy.”)

On health care, though, Barton said it was not a given that Republicans would oppose all the provisions in the health care reform package that emerged from the House and lamented “opportunities lost” where Waxman and other House leaders could have reached out to Republicans and forged compromises. He said Republicans took some risks by opposing both pieces of legislation.

“It wasn’t a given at the start of this Congress that it made [political] sense to be in opposition to cap-and-trade and health care,” he said.

Still, Barton has high praise for both Waxman and former Chairman John Dingell (Mich.), whom Waxman unseated at the start of this Congress, calling them both “starters on the Democrats’ A team.” And he offers praise for each of the Energy and Commerce subcommittee chairmen, even calling Rep. Bobby Rush (D-Ill.), the chairman of the Commerce, Trade and Consumer Protection panel and former Black Panther leader who couldn’t be more diametrically opposed to Barton ideologically, “one of the finest gentlemen I’ve ever met.”

But for all of Barton’s long history on Energy and Commerce, for all the relationships he’s developed there, his future on the panel — and the status of the Republican membership overall — is very much up in the air. At least four senior Republicans are moving on at the end of this Congress.

More significantly, it’s not clear whether Barton’s run as the committee’s top Republican (either as ranking member or chairman) will come to an end because of the House GOP Conference’s term-limit rules. That may depend on whether Republicans are able to retake the majority this November and on leaders’ interpretation of the rules.

Barton ran unsuccessfully for Senate in a 1993 special election that Kay Bailey Hutchison (R) won, and he is still occasionally mentioned as a possible candidate for statewide office.

“It’s a possibility. It’s not a probability,” Barton said of another Senate bid. “I’d really like to be chairman of Energy and Commerce again.”

Jeremy B. White contributed to this report.