Jon Huntsman is the one Republican presidential candidate who has refused to sign Grover Norquist's anti-tax pledge. I really like the understated, sinister tone of Grover Norquist takes here about their upcoming meeting:

The ATR pledge has evolved into something of a standard for GOP presidential candidates; former Massachusetts Gov. Mitt Romney (R) announced Thursday that he'd sign it, and Norquist said that all the other presidential candidates have either signed it already, or intend to sign it. (Former Minnesota Gov. Tim Pawlenty and Rep. Michele Bachmann, Minn., haven't signed, but Norquist said they've indicated to him that they'll do so.)
Norquist said he's arranged a meeting soon with Huntsman and his team, which the ATR president said might soothe the former Utah governor's concerns about the pledge.

Yes, Norquist is such a soothing guy: