Democrats Hillary Clinton and Barack Obama are setting their sights on a trio of presidential primaries on Tuesday that have gained unusual importance in the closest nomination race in recent memory.
Of little consequence in recent primaries, Washington, Maryland and Virginia have become key pawns in an electoral chessboard after Clinton and Obama shared the spoils of Super Tuesday this week, forcing them into a protracted battle for the Democratic nomination.
Virginia is the biggest prize of the lot with 83 delegates, while Maryland counts 70 of them. The US capital, which is not part of any state, offers 15 delegates.
The three primaries are of no consequence to the Republicans since John McCain emerged as the likely nominee yesterday after his top rival, Mitt Romney, dropped out.
But with little separating the Democratic contenders following the 24-state Super Tuesday, Clinton and Obama are campaigning hard for what has been billed as the "Potomac Primary" -- named after the river separating Virginia, Maryland and Washington.
The Democratic senators both have campaign stops in Richmond, Virginia tomorrow, while Obama plans to woo voters in other parts of the southern state on Sunday and Monday.
Before the Potomac Primary, however, the candidates face other contests this weekend in Louisiana, Nebraska, Maine, the northwestern state of Washington and the Virgin Islands.
In the most recent count by independent poll-tracker RealClearPolitics.Com, Clinton had 1,056 delegates, half of the 2,025 needed to capture the nomination.