As you no doubt heard, Eric Cantor bailed out of the talks to avert a debt default by the U.S. government. Cantor said he was leaving the talks because Democrats want to increase taxes. What he was referring to was a plan to eliminate tax breaks for oil companies (currently enjoying record profits) and large corporations that send jobs overseas. Eliminating those tax breaks would mean those companies would pay higher taxes, which is the tax increase to which Cantor referred.

The problem for Republicans is that most of them signed a pledge circulated by Grover Norquist in which they promised not to vote in favor of any tax increase. The pledge they signed carefully defined a tax increase to include any reduction in tax breaks. You can read the text of the pledge here: http://washingtonexaminer.com/blogs/beltway-confidential/2011/04/brief-history-coburn-norquist-tax-spat-and-why-it-matters

At least one of the Republican 2012 contenders has declined to sign Norquist's pledge:

<< Most Republican presidential contenders have signed since Norquist started demanding that they do so back in 1988. But there are signs that his grip on the Party may be weakening a bit, which presents an opening for Huntsman and a dilemma for Tim Pawlenty.

<< According to Norquist, five GOP presidential contenders for the 2012 nomination have signed a pledge that, if elected president, they will "oppose and veto" any "net" federal tax increase. The signees so far are not exactly a roster of front-row names: Herman Cain, Newt Gingrich, Rick Santorum, Gary Johnson and Ron Paul. Michele Bachmann hasn't signed, but is expected to do so.

<< "It's still early in the season," Norquist told The Huffington Post.

<< Mitt Romney signed the pledge when he ran and lost in 2008. He has yet to sign again, and on Tuesday his campaign announced that he would skip a debate Norquist's group was co-sponsoring in July with conservative news organization the Daily Caller.

<< Still, Norquist told HuffPost that Romney promised him the same day that he would take the pledge again despite kissing off the debate. "Romney told me personally that he would sign," Norquist said. >>

Source:
http://www.huffingtonpost.com/2011/06/21/grover-norquist-jon-huntsman-tim-pawlenty-no-tax-pledge_n_881857.html

If everybody who signed the Norquist pledge honors it, then the budget cannot be balanced.