This post has been updated.
In 2008, West Virginia's Democratic primary electorate was one of the most conservative and least liberal in the country. A fifth of Democrats who voted in the state's primary that year identified as conservative, according to exit polls, putting it in a select group with Louisiana, North Carolina, Texas and Mississippi (where a quarter of the Democratic electorate identified that way).
In 2012, the state's Democrats demonstrated their displeasure with the incumbent Democratic president by voting heavily for a guy who was serving time in prison. Keith Judd got over 40 percent of the vote; West Virginia, once a solid blue state, backed Mitt Romney that year by nearly 27 points.
This year, the state's Democrats exerted their independence in another way. Preliminary exit polls -- numbers that will be re-weighted as votes start coming in -- suggest that more Democrats who are voting for Bernie Sanders on Tuesday are likely to support Donald Trump in November than Hillary Clinton.
— Mosheh Oinounou (@Mosheh) May 10, 2016
But MSNBC's Steve Kornacki tweeted a more remarkable data point: Almost 4 in 10 Sanders voters plan to support Trump over Sanders.
There are usually some people in exit poll data who say they'd vote against their preferred candidate in the general election. After all, the general election offers different choices than the primary, and if you're a conservative Democrat, you may think that Sanders is preferable to Clinton or vice versa, but also that a Republican would be preferable to both.
In Pennsylvania, exit polls reported by CNN indicated that 2 percent of Clinton and 5 percent of Sanders voters would vote against those candidates if they won the nomination. So it's really the scale that's surprising here, not the existence of the phenomenon.
Update: Some other preliminary exit poll nuggets, reported by CNN. About 4 in 10 West Virginia Democrats would like the next president to be less liberal than Barack Obama -- a substantially higher figure than in other states, where the average has been 11 percent. Six in 10 of those voters, oddly, went for Sanders, who usually does better with more liberal voters. Sanders did about as well with moderates and self-identified conservatives in the state as he did with more liberal ones. NBC reports that those conservatives backed Sanders over Clinton.
About a third of the primary electorate, according to preliminary exit polls reported by ABC, identify as independents -- a significantly higher percentage than in most states. (The electorate is also more heavily male than the average to-date. That group has consistently voted against Clinton.) More voters identified as Republicans, according to early exit polls, than in any other state for which we have data. The only one that's close is Oklahoma.
Fun fact about WV: It was the only state with more total Dem primary votes in '08 than Dem GENERAL election votes that year. #WVPrimary
— Geoffrey Skelley (@geoffreyvs) May 11, 2016
So should we take this party defection at face value? Sure, why not. Trump is almost certainly going to win the state (Cook Political's forecast puts it as a "Solid R" for the general), and he'll likely win it with the help of Democratic votes. (Romney won 62 percent of the vote in the state in 2012 -- even as the Democratic governor won reelection with a majority.) If the polls are correct and Bernie Sanders wins Tuesday night, there may be some chunk of that vote which is meant to be oppositional to Clinton, the likely party nominee.
West Virginia's Democrats aren't like Democrats in other states. They weren't in 2008, they weren't in 2012, and there's no reason to assume they will be this year. Could four in 10 voters today come out and vote for Trump in November? It seems hard to believe. But: Yes, they could.