Super Tuesday taught this lesson: It's not just the state that matters, it's also the delegates.

The rule now comes to Maryland, Virginia and the District of Columbia, where 168 delegates are available for Democrats next week and 116 for Republicans.

Among Democrats, Sen. Barack Obama of Illinois might carry all three jurisdictions, but whether he leaves the region Tuesday with a healthy delegate edge will be determined by his support in places such as Baltimore, Rockville and Landover.

Huge wins by Obama in the Washington area could give him a few extra delegates that could become critical in the nominating process.

For Sen. Hillary Rodham Clinton of New York, the task is doing as well as possible, while keeping Obama's margins low.

Her campaign strategists said yesterday that even a sweep by Obama might not provide him with an edge of more than 15 delegates.

Delegates are awarded by formulas that take into account where the votes come from, so certain counties and neighborhoods in Maryland take on added importance.

For Republicans, the counting is relatively straightforward, and all contests are essentially "winner take all," with slight modifications. Sen. John McCain of Arizona appears well positioned to carry all of the 37 Republican delegates available in Maryland.

The math is more complex on the Democratic side. The party tries to award delegates in proportion to the vote totals of each major candidate.

Here's how it works:

For Democrats, Maryland has 99 delegates, with 70 to be awarded Tuesday. The remainder are so-called "super delegates" - the elected officials and other party leaders who aren't bound by voters' wishes and are being heavily courted by both candidates.

Of the 70 delegates, 46 will be decided by votes in congressional districts, with the number varying based roughly on the number of Democrats there.

Two districts offer seven delegates apiece, the most of any.

They are the 4th, in Montgomery and Prince George's counties, represented by Rep. Albert R. Wynn, and the 8th, mainly in Montgomery County, represented by Rep. Chris Van Hollen.

Wynn's district contains many wealthy and middle-class African-American voters and is a place where Obama is expected to do well.

If Obama wins 51 percent or 60 percent of the vote in those districts, he would win the same number of delegates: four, to Clinton's three.

But if his vote total gets above 64 percent in those two districts, he would get rewarded with an extra delegate, taking five, while Clinton would get two. That provides an additional incentive for supporters and campaign aides in those areas to work harder.

The figures are different in other districts.

There are six delegates apiece available in three districts: the 3rd, represented by Rep. John Sarbanes; the 5th; represented by Rep. Steny H. Hoyer; and the 7th, represented by Rep. Elijah E. Cummings.

In those districts, Obama and Clinton will get three delegates apiece unless one of them cracks the 58 percent threshold. Then, that candidate would get four delegates, while his or her opponent gets two.

A delegate pickup is a clear possibility in the district of Cummings, who is state co-chairman of the Obama campaign.

State Del. Curtis S. Anderson, an Obama supporter who lives in the 7th District, said volunteers are working on aggressive get-out-the-vote efforts but don't necessarily have the 58 percent threshold in mind.

"We haven't gotten that precise in terms of trying to win the district," Anderson said. "It's more of a shotgun approach. We are trying to get people out to vote who haven't voted in the past."

Twenty-four additional delegates are awarded proportionally based on the overall state vote.

If Obama carries Maryland by a 57 percent to 43 percent margin, he would get 14 of those delegates, compared with 10 for Clinton.

But if Clinton keeps Obama's winning percentage at 56 or less, the split of the statewide delegate portion would be 13 for Obama and 11 for Clinton.

Republicans award three delegates apiece to the winner of each of the eight congressional districts and an additional 13 to the overall state winner.

While McCain stands a good chance at gaining all 37 delegates, supporter Donald Murphy, a lobbyist and former state delegate, said that former Arkansas Gov. Mike Huckabee or former Massachusetts Gov. Mitt Romney could earn a few delegates in Western Maryland or on the Eastern Shore.

"I think Huckabee is our opponent" in the 1st District, represented by Republican Rep. Wayne T. Gilchrest, and in the 6th District, represented by Republican Rep. Roscoe G. Bartlett, Murphy said.

But even if Huckabee carries both districts, McCain would leave Maryland with a 31-6 delegate advantage.

david.nitkin@baltsun.com