Yes They Will:
1. He's the latest in a line of potential GOP presidential candidates to fall victim to his personal appetites. This means that the GOP primary electorate is more likely to choose a nominee with stellar, unimpeachable family-values, socially conservative credentials, which means that anyone who evinces moderation hasn't got a shot. Remember: Rudy Giuliani lost the presidential race because news reminded voters about his previous indiscretions.
2. Gov. Haley Barbour, as the new RGA chair, is the most powerful Republican in politics today, second only, I think, to Mitt Romney. Barbour has always craved a return to the respectable power circles in Washington. The race just lost a real Southerner, ceding to Barbour the GOP's juiciest territory. Watch for Barbour to be more aggressive about his national ambitions. (I'm not saying he WILL run for president, just that he wants to.)
3. The GOP loses one of its most articulate anti-spending, anti-deficit spokespersons. Sanford's machinations may not have been popular, but he articulated a view of the world that many conservatives share. He was to many the face of opposition to President Obama's increasingly unpopular stimulus bill.
4. The topsy-turvy world of South Carolina Republican politics is now even more chaotic, if you can believe that. This may give Democrats a chance to move in that state.
5. The media will have more license to investigate rumors of personal indiscretions, and politicians will be more defensive. A few years ago, the media would ignore the rumors, owing to a post-Clinton detente/public wariness about the private lives of politicians. Not anymore.
6. This may be a tipping point: a few examples of conservative moralists who cheat on their wives (Vitter, Ensign) can be, perhaps, accepted as evidence that human beings are normal. But at some point, the liberal talking point about GOP hypocrisy starts to have the ring of truth, even though plenty of Democrats have been implicated in affairs of their own. Moralizers in politics don't have the clout they once did, and Sanford joins the list of politicians who are responsible. The usual "blame the culture of New York and Washington" line, which was used to explain the indiscretions of the two most recent New York Democratic governors and of Senators Ensign and Vitter, don't apply to Sanford. He was as South Carolinian as all get out.
7. The GOP will find itself distracted at a time when the party needs to be disciplined on health care and energy. Every GOP officeholder will be forced to spend valuable time explaining why their party stands for family values.
No They Won't:
1. As one correspondent put it to me, the GOP is at a market bottom already. The public's image of the party can't really go down much further.
2. Most Americans probably didn't know who Sanford was before today, so it'll hard to attribute any massive change in politics to his sudden emergence.
3. Sanford was never a viable 2012 candidate because of his eccentricity; to put him in the same category as a Mitt Romney or a Sarah Palin misjudges the impact he would have had.
4. What policy will change because of this? It's a fantasy to think that voters will get the joke about how gay people keep ruining straight politician's lives.
5. Enough already. Wars, economic crises, major reform of health care and fiscal policy, Jon and Kate, the Iranian revolution: our collective bandwidth may be at capacity.
6. Logically, Mark Sanford's affair tells us nothing about the rightness or wrongness of policy (although it does hurt the way one particular brand is sold.)