[koenigdavidmj]

That doesn't explain Washington State, where the Democrats didn't use their state-provided primary at all (all of their primary delegates were allocated by a caucus you had to attend) and the Republicans did (though only one candidate is running now, so it doesn't really matter).

The Democrats made you physically get up on a Saturday and go, unless you had a valid excuse. Elections in Washington are by mail, so to vote in the Republican primary, you only had to walk to your mailbox.

[delecti]

That's irrelevant, because the turnout in-person among Democrats isn't comparable to the turnout via mail of Republicans.

[debracleaver]

vote-by-mail patters are changing, however, to be more representative of the electorate as a whole. i think it tended to skew more conservative in the past because the RNC invested considerable resources into VBM programs. the DNC has been a little later to the VBM process.