Just how deadly are scandals for American politicians? We've certainly seen plenty of political careers cut short by extramarital affairs or financial misconduct, but we've also seen politicians like Bill Clinton not only weather scandal but seem to emerge stronger and more popular from the experience. Why is it that some politicians seem to be able to ride out difficult storms while others founder? Are some storms worse than others?
Scott Clement at The Fix had a fascinating post up last week analyzing 38 congressional sex scandals since 1974. The analysis found that not only are the odds against a scandal-plagued incumbent maintaining his (yes, these were all men) seat, but those odds have gotten worse over time. This doesn't bode well for Representative Vance McAllister (R-Louisiana), whose short congressional career is now threatened by his kissing a married staffer.
Context also matters. Your allies may be quick to abandon you during a scandal if you're expendable (think John Edwards), but if you're, say, the president, they may be more likely to rally to your side.
Political scientists have also looked at these questions. Brandon Rottinghaus (PDF) examined scandals in presidential nominations contests since the 1990s and found a curious pattern: Scandals seemed to harm fundraising but actually improve the candidate's prospects for winning the nomination. There may be a few things driving this. For one, the scandal may actually increase awareness of the candidate—voters hear more about the contest thanks to the scandal and start paying attention to the candidate, and they may actually like what they see (apart from the scandal itself). These scandals may also be more likely to emerge among the candidates with a better chance of winning. (More on this below.) Other research by Rottinghaus (PDF) suggests that presidential scandals are more durable when there is a larger party opposing him in the Congress (presumably one with subpoena powers).
Scott Basinger, meanwhile, looked at over 250 scandals affecting members of the House of Representatives over the past four decades, finding that scandal seemed to reduce re-election margins by around five percent—roughly erasing the typical advantage incumbents have when running. This may well understate the penalty, as many incumbents facing the most serious scandals resign their seats before the next election. One way or another, Basinger finds, roughly 40 percent of House members facing scandals will not be in office for the next session. An earlier study by John Peters and Susan Welch found a vote penalty ranging from six to 11 percentage points.
Context also matters. Your allies may be quick to abandon you during a scandal if you're expendable (think John Edwards), but if you're, say, the president, they may be more likely to rally to your side. Scandals may also be more damaging for black candidates (PDF) than for white ones. Additionally, scandals may be more likely to emerge when the opposition party has a lower opinion of the incumbent and when it's a slow news week (PDF). Voters think worse of scandals involving financial problems than they do of sex scandals, especially when abuse of power is involved. They are also quicker to forgive (or forget) sex scandals than financial ones (PDF).
The studies all seem to confirm the idea that scandals are serious and do exact a price from politician's careers. Yet a lot of this research remains plagued by selection bias. That is, scandals may be more likely to emerge among the better candidates or more powerful officeholders. This isn't because better politicians are more likely to cheat on their spouses (although that would be interesting!), but because no one's going to bother to research and dig up scandals against a politician whose career isn't going anywhere. Why waste effort destroying someone who poses no threat to you? It's more often the serious politicians whose lives will be investigated with a fine-toothed comb. Which means that scandals may actually be more damaging to political careers than they seem.
On the other hand, we also know that many politicians resign almost immediately upon a scandal's emergence rather than test their fate with the voters. They do so partially on the belief that they're going to lose anyway, partially due to pressure from allies in their party, and partially because they just don't want to have reporters camped out in front of their houses anymore. And who can blame them? But we don't actually know how they would have done if they'd just refused to resign. As Bill Clinton and David Vitter showed, you can survive some scandals, but that can take a toll on your personal or family life that many politicians just aren't willing to pay.
Thanks to Brendan Nyhan for help in researching this post.