Congressional Republicans know they can’t stop a tax increase — but they’ll be damned if they let President Barack Obama get a debt limit increase for free.

The statutory ceiling on the U.S. debt, according to GOP lawmakers, staff and conservative interest groups, remains their strongest leverage in getting the president to come to the table with deeper spending cuts — now and in the future. And Obama, in his opening offer in fiscal cliff negotiations, proposed eliminating the need for Congress to affirmatively raise the ceiling, arguing politics should not affect whether the U.S. government meets its obligations.

But since the president made that offer, Republicans have dug in on the issue, becoming almost preoccupied by their need to preserve that point of leverage during Obama’s second term.

“It’s all our guys want to talk about,” one senior Senate Republican aide said. The aide noted that Democrats should not misjudge the GOP’s willingness to hold the debt limit hostage and that the party will be in no mood to compromise on the issue if Obama keeps insisting on a massive tax increase.

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