Under new Oregon law, all eligible voters are registered unless they opt out

[Gothmog]

76. But they still have to register their party affiliation on or before 21 days before the primary

Automatic registration means that new voters who get their drivers license are automatically registered unless they opt out. People who not getting drivers licenses http://sos.oregon.gov/voting/Pages/motor-voter.aspx

How it Works
Automatic voter registration is available if you are eligible* to register to vote and you apply for your original, renewal, or replacement license, permit, or ID card at the DMV.

Once you engage the Oregon Motor Voter process by visiting the DMV, you will receive a card and a pre-paid postage return envelope from the Oregon State Elections Office.

With this card, you have three options:

Do nothing. You will be registered to vote as a nonaffiliated voter (not a member of a political party).
Choose a political party by returning the card. Joining a political party will allow you to vote in its primary elections.
Use the card to opt-out and decline to register to vote.

Once registered, you will automatically receive a ballot and instructions in the mail about two weeks before an election. When you vote, your ballot is secret and your choices cannot be matched up with your name.

Oregon is a closed primary and ballots will be mailed only to voters who indicated that they are members of the Democratic Party on or before 21 days prior to the primary.

Does anyone want to bet how many people forget to register as democrats? Again, you can vote in the general election without regard to party affiliation so long as you are registered as described above.

BTW, the Oregon law is wonderful but it is still tied to people getting Drivers' license or who are otherwise in the system. As part of the process, the voter still affirmatively has to elect to affiliate with a political party on or before 21 days prior to the primary