By Joseph J. Schatz, CQ Staff

It used to be that any “gang” of Senate centrists seeking a big legislative deal would have John McCain at its core — to the chagrin of Republican Party leaders.

Not anymore.

While a large group of Senate moderates worked behind closed doors in the Dirksen Building last week to fashion a compromise plan to trim the stimulus plan by some $100 billion, the original maverick was on the floor, leading conservative GOP opposition. McCain, R-Ariz., a longtime fiscal conservative but not always a tax cut advocate, said the plan is too costly and full of wasteful spending. He offered a more tax-cut-focused, $421 billion substitute plan, which was blocked on a procedural motion.

Back in 2005, McCain was a key member of the “Gang of 14” that found a compromise and avoided a Senate meltdown after then-Majority Leader Bill Frist, R-Tenn., threatened to invoke the so-called nuclear option to end Democratic filibusters of Bush administration judicial nominees. And he was a key member of many other small groups working to reach deals on issues ranging from the budget to energy policy.

But in a brief interview last week, the recently defeated GOP presidential nominee said the current group, which ranges from 15 to 20 senators, was hardly bipartisan. It was a far cry, he said, from the old gang, which had an even partisan split.

“The Gang of 14 was seven and seven,” McCain said. The current group has about 15 Democrats and three Republicans, he said. “That’s not bipartisan. That’s a joke.”

(Other senators involved in the effort, including Claire McCaskill , D-Mo., have put the number of Republicans involved higher.)

For now, at least, McCain is firmly back in the GOP column, much to the pleasure of his more orthodox colleagues.

“It’s nice to be side by side with the guy you respect and admire so much,” said Saxby Chambliss , R-Ga.