PSA: Voter Registration Deadlines for Closed Primaries in MD and PA
April 26 features several closed primaries in the northeast. Independents will not be able to vote unless they are registered as Democrats. Voters must be registered 21 days in advance in MD and 30 days in advance in PA in order to vote in the closed primaries in those states on April 26.
That means the PA registration deadline is just a few days away and the MD deadline is a couple of weeks away.
Here is a handy site with basic information about voter registration and deadlines for every state.
http://votesmart.org/elections/voter-registration
For more detailed and specific voting laws, the respective state sites should be visited as some important information, such as New York's highly restrictive party affiliation changes for primaries is not mentioned on this site.