Should Tax Cuts Be Paid For?

Senate Budget Committee Chairman Don Nickles (R-Okla.), an opponent of such restrictions on tax cuts, also said passage of the House measures probably would have made little difference.

But other moderates strongly disagreed. If left to their own devices, a majority in both chambers support stricter controls on tax cuts and spending, said Rep. Charles Bass (R-N.H.), who voted for both Democratic motions. Passage "would have given the moderate Republican senators a chance," he said. "It's just sending a signal to them to stand firm."

Snowe agreed: "It would have given us something to point to."

Arcane as budget rules may be, the issue of "paying for" tax cuts has become central to GOP politics, budget experts said.

"What we're seeing playing out here is what the level of future taxes will be," said Robert Reischauer, a Democrat and former director of the Congressional Budget Office. "It's vital to the Republican Party."

June E. O'Neill, another former CBO director and a Republican, said the GOP leadership's position has "intellectual merit." Applying the same rules to tax cuts as spending hikes creates an equivalency where none should exist, she said.

"A tax cut does have stimulatory and growth effects that are not true for government expenditures," she said.

But for GOP moderates, the merits of the opposing arguments appear lost amid tactical tussles, and between the pull of party loyalty and the push to stand their ground.

"I've taken on this role to be inside the tent, to be the midway point between the moderates and the conservatives on this issue," Kirk said.

To that, Bass countered: "It's all the way you work. I don't sign letters every day, and when I do, I try to do what I say I'm going to do."