Democratic state Rep. John Bel Edwards beat Sen. David Vitter yesterday to become Louisiana's next governor. The outcome was predicted by the polls but still counts as fairly surprising given the drubbing Democrats have taken in state politics, especially in the South.

Every race is a beautiful, unique snowflake, but there are some lessons you can learn from each one.

1) Louisiana was a perfect storm

A number of different factors came together to power Edwards's win. One is that Edwards, as a former Army ranger with deep family ties to Louisiana state politics, had the right kind of biography to win in a red state. The other is that Vitter's rather unusual history with paid sex gave him the wrong kind of biography to win in any state. Add to that the fact that the Louisiana Republican Party is divided and factionalized and the GOP has a firm grip on the state legislature, so some Republicans aren't exactly weeping to see Vitter lose.

Last but by no means least, the Louisiana economy is suffering from the global trend toward cheaper oil in a way that naturally helps challengers.

2) Medicaid is a good issue for red-state Democrats

Nothing works everywhere all the time (see Democrats' recent loss in the Kentucky governor's race) but running as the party that is willing to accept the federal Medicaid dollars made available under the Affordable Care Act continues to look like a smart strategy. This was the issue on which Edwards positioned himself as an orthodox Democrat, and he won. It's also the issue on which a number of Republican governors in the Midwest and Southwest have felt the need to compromise.

Medicaid expansion is something liberals and moderates in the Democratic Party can agree on. Better than that, it's something that liberals perceive as having sufficient moral urgency to make them enthusiastic about backing moderate candidates whose views they may not like on other matters. But it also expands Democrats' interest-group coalition, since a wide range of hospitals and other health providers can be counted on to back expansion.

3) Demographics matter

Louisiana is about one-third African American, with a modest but growing Latino population. That makes it possible for a Democrat to win a majority in the state while still getting crushed among the 60 percent of the population that is non-Hispanic white.

For a long time, Democrats were generally stronger in the whiter Southern states, places like Arkansas, West Virginia, and Kentucky where racial politics were less polarized. These days, Democratic hopes for a revival in the South likely rest less on those places than on states like Georgia and Louisiana, where large black minorities make winning the hearts and minds of the white South less urgent.

4) Republicans are still winning the long tail

The governor's race is the highest-profile and most important race in state politics, just as the presidency is the most important contest in the United States. But the Louisiana GOP continues to hold all of the state's other statewide offices and both houses of its legislature.

In other words, Democrats beat a weak candidate with a strong candidate in an unusually important race. What they didn't do was leverage Louisiana's economic problems and the internal divisions in the Louisiana Republican Party into any kind of larger victory.

5) Democrats' next Southern hope is North Carolina

The next place to look for signs of a possible revival for state-level Democrats is North Carolina. This is a Southern state, and a red one, but Barack Obama did carry it in his landslide 2008 victory. And the Democrats' likely 2016 nominee — Attorney General Rory Cooper — is one of the few Democrats with a proven track record of winning statewide elections in the South in the Obama years.

Even better for Democratic hopes, North Carolina is one of the relatively few states that holds gubernatorial elections in presidential election years. Democrats' problems in state politics go beyond turnout, but the fact that Democratic Party supporters are much less likely to vote in midterms doesn't help.