Ohio has a closed primary.
Do I declare my political party affiliation when I register?
No. Under Ohio election law, you declare your political party affiliation by requesting the ballot of a political party in a partisan primary election.
If you do not desire to affiliate with a political party in Ohio, you are considered to be an unaffiliated voter. An unaffiliated voter does not vote the ballot of a political party in a primary election. However, an unaffiliated voter may vote the Official Questions & Issues Ballot, if there is one for the voter’s precinct at the election. Ohio voters FAQ
Voter Registration Form
Or copy/paste the address into your browser:
Voters who voted in the primary of another party in the previous election must complete a statement at the polls that confirms their changed affiliation. (Source: http://www.fairvote.org/open-and-closed-primaries)
Registration Deadline: Feb 6, 2012 (Certainty: confirmed)
Primary Date: Mar 6, 2012 (Certainty: confirmed)