In the wake of a dismal third-place finish with less than 1 percent of the delegates in Iowa, former Maryland Gov. and Baltimore mayor Martin O'Malley is ready to suspend his campaign, a source confirms to Vox.

On paper, his presidential run made sense. As the leader of a blue state and working in partnership with Democratic majorities in the state legislature, O'Malley racked up a considerably more progressive record than Hillary Clinton's while remaining a mainstream Democrat who was broadly liked and acceptable to his co-partisans in a way that isn't true for Bernie Sanders. Obviously, any challenger to Clinton would have been an underdog. But with Elizabeth Warren taking herself out of the picture, rallying behind O'Malley could have been the labor-left wing of the party's best chance at dethroning her.

Instead, Clinton moved swiftly to address key interest group concerns — turning against the Trans-Pacific Partnership and the excise tax on high-value health insurance plans — and locked down early endorsements from key labor unions. Then, with the entire establishment behind Clinton, Sanders's pure outsider vision of robust social democracy caught fire with elements of the grassroots. It quickly became a two-candidate race in which O'Malley was playing little substantive role other than waiting in the wings in case one of the other two was hit by a bus.

It's been so clear for so long that he's not going to win that it's barely news he's dropping out. But it's worth dwelling for a moment on the extent to which, by conventional terms, it was O'Malley who seemed like the most solid candidate in the race. Unlike Clinton, he's been a fairly consistent liberal throughout his career. And unlike Sanders, he's been a fairly mainstream Democrat throughout his career.

Martin O'Malley was an excellent governor of Maryland

If you are looking for a recent example of a state where a bunch of Democrats held political power, used that power to pass a bunch of liberal laws, and ended up with their state in a pretty good place, you could do a lot worse than Martin O'Malley's Maryland.

Under O'Malley, taxes on the rich went up. So did the gasoline tax. The state curtailed gun rights and expanded same-sex marriage rights. It passed a state DREAM Act and capped college tuition increases. Maryland is also the home to a health care cost control policy known as the all-payer rate setting that is generally liberal wonks' dream. O'Malley expanded mass transit in his state and helped develop an alternative to GDP to measure real progress in living standards. Even a hideously unpopular O'Malley initiative like the so-called "rain tax" on impermeable surfaces was actually a perfectly reasonable idea.

Not only did O'Malley do a lot of liberal stuff, but the outcomes were worth bragging about. Maryland has the highest median household income of any state, the most college graduates, and under O'Malley it had the nation's best-scoring K-12 students too. Maryland is a bottom 10 state in terms of per capita carbon dioxide emissions. It's the kind of record that might have made for a good presidential campaign. If the average American were as a rich, educated, green, and healthy as the average Marylander, we'd have made enormous progress as a society.

Governors used to be cool

That O'Malley hasn't caught fire is understandable enough, but it seems to be part of a larger 21st-century trend in which presidential politics' historic preference for governors has shifted in favor of senator-centric nomination battles that see Clinton, Sanders, Marco Rubio, and Ted Cruz all rating higher than an O'Malley or a Rick Perry or a Scott Walker.

There's something at least a little troubling about this trend. The presidency is, among other things, a complicated administrative job that seems to have a lot in common with being chief executive of a state. But the nationalization of politics appears to have created a dynamic in which nomination contests are more about who you are than what you've done, in a way that favors deep engagement with the national media ecology over the inevitable fuzziness that comes with running an institution.