There’s a lot of interesting overlap with what’s happening in the 2016 presidential race, too.
No candidate has benefited more from the surge in political independence than Sen. Bernie Sanders of Vermont. As we’ve noted, in states for which we have exit polling, at least 30 percent of Sanders’s overall support comes from independents pretty consistently — and in some states that figure creeps up to nearly 50 percent.
That’s one reason that Hillary Clinton blew him out in New York. There are a lot of independents who lean toward the Democrats who wanted to vote for Sanders, but the state’s primary system — a closed primary in which only registered Democrats can vote — meant that they weren’t able to. Having them vote probably wouldn't have changed the lopsided outcome, but, combined with the early deadline for changing registration, it provided for a lot of frustration.
But there’s an interesting footnote to that. Despite the closed primaries, according to exit polls conducted by Edison Media Research in New York and reported by CNN, 14 percent of those that turned out to vote in the Democratic primary identified as independents. More than one-fifth of Republicans did the same.
How? Because as Edison’s Joe Lenski reminded us when we walked through how his process works, this is a self-identification, like Gallup’s. Just as there’s a chunk of independents who act like Democrats, there’s a chunk of Democrats who act like independents. Party registration is a thing you do, not what you are.
There are three ways in which states filter who can participate in caucuses. There are closed caucuses, like New York’s. There are open ones, in which anyone can vote. And there are modified open ones, in which unaffiliated voters can vote in a party primary, but the other party can’t. This is very much oversimplified, but it helps us categorize the states that have voted already.
When we do so on the Republican and Democratic sides, here’s how the party/independent splits look overall and on average for each type of primary. (The primary types come from RealClearPolitics.)
Interestingly, the highest density of independent voters is in those modified primaries. But in each case, there’s a healthy chunk of the electorate who came out to vote and who considered themselves independent.
How many were registered with a party? It’s hard to know, except in those closed primary states. Since people often misreport their actual voter registration (it's surprisingly easy to forget), it’s hard to know where the boundaries between independent Democrat and Democrat-leaning independent lie.
This, too, explains the rise of Sanders. He’s an independent who registered as a Democrat for the purposes of the 2016 election. Far from abnormal, it’s simply how things work these days.