The District, Maryland and Virginia are all heading to the polls tomorrow in a historic all-Potomac presidential primary. It's such an unusual primary schedule that, especially in the tight Democratic race, it's made the delegates up for grabs in the region significantly more important than they often have been in the past.

If you haven't run in to an Obama or Clinton canvasser in the past three days, you apparently haven't been getting out at all. Former DCist editor Rob Goodspeed sent us this impressive (if blurry) image from his camera phone of almost 20,000 Obama supporters gathered at a rally earlier today at the Comcast Center at the University of Maryland. Sen. Hillary Clinton even made her first personal campaign appearance in the District earlier today, and pledged her support for granting the District voting rights in Congress. We can't remember the last time leading presidential candidates even bothered to address issues only voters in the District of Columbia care about.

All the polling and demographic data suggest Sen. Barack Obama is going to sweep the Democratic primaries tomorrow, and Sen. John McCain looks set to have no trouble continuing his momentum in our region on the Republican side. But that doesn't mean your candidate of choice, whoever he or she may be, doesn't need your vote tomorrow. Especially for District residents, we consider this a rare opportunity to affect national politics.

To find or verify your polling place for tomorrow, follow the links below:

District of Columbia - Head to the DCBOEE's polling place locator tool. It's not the most intuitive search function - note that you need to enter only your street number in the first box, then the street in the second, and then the quadrant in the third. You can also search through all the polling places here. If you're not sure if you're registered to vote, you can use this tool to find out, which we've been assured by folks at DC.gov is now working properly again. Polls in D.C. are open 7 a.m. to 8 p.m.

Virginia - The entire state of Virginia can search for their polling places through the state's VERIS system. You search by voter registration or search by address. Don't get confused: Virginia polls are open 6 a.m. to 7 p.m., one hour earlier than polls in D.C. and Maryland.

Maryland - You can search for a polling place in Maryland by voter registration here. They don't allow you to search only by address, so if you have a problem, you should contact your local county's election office. Polls in Maryland are open 7 a.m. to 8 p.m.