The Fix
By Philip Bump
September 15, 2014 at 1:07 PM

As voter registration deadlines before the November general election begin to pass, new disputes over voter registration efforts have erupted. In the wake of the shooting of Michael Brown in Ferguson, Mo., Democrats launched a voter registration effort, angering some local Republicans. More recently, a registration effort led by a Democratic Georgia state representative — which has turned in a number of new voter applications — is being investigated by the Republican secretary of state.

Every vote counts, as they say, but one longstanding bit of conventional wisdom in political campaigns is that newly registered voters aren’t likely to vote. In part, that mentality stems from the fact that, with limited resources, it makes more sense for campaigns to target voters who they know have voted before. Voting is, after all, a habit.

But in light of this year’s elections, we thought the whole thing was worth investigating.

Political Data is a California-based … well, political data firm. The firm’s Paul Mitchell was generous enough to compile data on the voting history of recent California elections, based on people currently registered to vote in the state. We parsed the data to figure out how much new voter registration efforts actually correlate to turnout, in California at least.

This is the very top line, comparing all voters in the state with people registered since the last statewide election. Interestingly, you can see that turnout among the newly registered voters matches or even exceeds the turnout for the voting population as a whole — in general elections. They are substantially less likely to vote in primaries.

But in pulling the numbers Mitchell included a set of data that relates to something the firm had noticed in its work. People registered to vote shortly before Election Day were more likely to vote than people who were registered at other times during the year. They’re marked as “late registration” on the graph below, reflecting people registered after January (for a primary) or after September (for a general).

There’s still the dichotomy between generals and primaries, but in general elections, late registrants have been significantly more likely to vote than the voter pool on the whole.

There’s one demographic set where this difference between new and established voters is particularly noticeable: age. (When we say “established voters” here, we really mean “all voters,” which is mostly voters who have been registered for a long time.) This is what turnout has looked like overall for the last eight statewide elections in California, by age.

To read entire story, click here.