Just a week before a much-ballyhooed visit to the key presidential primary state of New Hampshire, House Speaker Newt Gingrich hasstirred confusion aplenty on the campaign trailby telling Business Week that he might run for president if 7 million voters signed petitions urging him to do so. "Gingrich simply refuses to close the door on a presidential bid," saysMichael Duffy, TIME's national political correspondent. "If anything, he has opened it a bit with these comments." The immediate effect is tosteal thunder from the nine GOP candidatesalreadytrying to raise money and support. Gingrich maintained today that he was only half-serious in his comment to Business Week. Maybe so, but the excited reaction among GOP activists to renewed talk of a potential Gingrich candidacy was telling. Duffy notes: "The longer he stays out there playing footsie with a presidential campaign, the longer it freezes in place the voters and backers who might be inclined to support him, and prevents other candidates from signing them up."