Potomac Primary

Tomorrow, Maryland, Virginia, and the District of Columbia will vote in a sort of regional presidential primary -- very handy for the campaigns, who will be able to maximize the value of ad time purchased on Washington television. On the Republican side, Virginia and DC are winner-take-all, awarding 63 and 16 delegates respectively. Maryland is winner-take-all by congressional district: 3 delegates for winning each of eight congressional districts, and 13 statewide delegates. The RNC members for all three jurisdictions, who are ex officio national convention delegates, will be bound to the winner of their respective jurisdictions.

Virginia has an open primary. Will centrist, Independent types, John McCain's electoral bread and butter, decide the Republican primary is all but over and decide to use their influence in the Hillary-Obama war? Will that allow Huckabee to sneak in and take Virginia?

Maryland and DC have systems much like Oklahoma's -- they have closed primaries, the registration books close a few weeks before the election, and there are restrictions on when you can change parties.

John McCain, by my estimate, has only 683 delegates bound to vote for him. Including tomorrow's delegates at stake, there remain only 725 bindable delegates to be allocated. He will need to win 70% of those remaining delegates in order to be guaranteed the nomination.

Last Saturday, Mike Huckabee was the only delegate winner, taking the 36 Kansas delegates at stake. The Washington event was a non-binding straw poll.

Huckabee might have won 20 more in the Louisiana primary, but he fell short of the required 50% of the vote. That means all of Louisiana's delegates will be elected at Saturday's state convention. They will not be bound in any way, but the state convention will likely choose national delegates based on presidential preference. Which candidate the state convention is likely to support is unclear, as the bulk of the delegates to the state convention were elected on a "pro-family, pro-life" uncommitted slate.

MORE: Jim Geraghty links to a good explanation of the actual process in Saturday's Washington State precinct caucuses and why the reported straw poll results are meaningless in determining the makeup of the state's delegation to St. Paul. What the Sound Politics blogger says about the Washington caucuses is true in other caucus states where non-binding straw polls have been taken, such as Iowa, Maine, Nevada, and Minnesota.