The reason Democrats should be clamoring for a strong candidate to take on Hillary Clinton in the 2016 primaries isn't Whitewater. It has nothing to do with the political baggage she has been carrying during her long public life.
The issue has come up because of a fuss over a Harper's magazine cover story saying Democrats should "Stop Hillary!" based on two things: the Clinton scandals of the 1990s and earlier, and the objection that the only case for her candidacy is that "she has experience, she's a woman, and it's her turn."
Whether this argument holds up (and, as political scientist Scott Lemieux argues, it doesn't), Democrats of all stripes should be clamoring for a contested race.
The first reason to want a primary is that the more likely it is she can secure an uncontested nomination, the less she will have to commit to the Democratic platform. The nomination process cements candidate to party; without it, the natural tendency of politicians is to maintain as much independence as possible.
Now, it isn't as if even an uncontested Clinton could ignore the party altogether. If she wasn't signaling her support for what Democratic activists and Democratic-aligned interest groups want, they wouldn't be lining up behind her. And she is a creature of her party to begin with. Her campaign organization and, if elected, her administration will draw from the same pool of party professionals that any Democratic presidential contender would turn to. Still, the more a nominee can be pushed toward the party, the better off the party is.
There's a different reason that those who find the current Democratic Party and its likely nominee too conservative would want a competitive primary season. Parties are self-defining institutions, and the main way they go about defining themselves is through nominations for office. Parties take the positions they do because their leaders support those positions, either for policy or electoral reasons or both. Still, it's always possible to change a party. But it is far easier to achieve this change by forcing the eventual candidate to adjust his or her positions during the presidential nomination process than it is to try to change the positions of an elected president.
This process can work even if Clinton wins every primary and caucus, as long as there is enough opposition to force her to compete seriously. The positions of other candidates don't matter as much as what the Democratic Party collectively believes -- and whether it can find the leverage to force its nominee to firmly support those policies. No matter who opposed her, and which issues the challenger raised, both Clinton and her opponent would be competing for the support of the bulk of the party.
What's important for the process to function is to recruit a candidate who can force a real campaign.
The difficult part is to entice a potentially formidable candidate to go up against Clinton, even though her nomination would be perfectly pleasing to the mainstream liberal bulk of the party.
Still, even Democrats who strongly support Clinton should hope someone challenges her, but not because of ancient and probably irrelevant baggage such as Whitewater and Travelgate, and not even because of her vote for the Iraq War. An unchallenged candidate is an independent politician, and party actors should want party politicians.
Jonathan Bernstein is a Bloomberg View columnist.