RICHMOND, Va. (AP) _ Barack Obama continues to rack up the wins
against Hillary Rodham Clinton, while John McCain defeated Mike Huckabee in an unexpectedly close Republican primary in Virginia.

Obama and McCain swept Tuesday's "Potomac Primaries," picking up wins in Virginia, Maryland and the District of Columia.

The Associated Press made its Democratic call based on surveys
of voters as they left the polls. According to preliminary data from exit polls of voters conducted for the AP and the television networks, Obama was getting the backing of two-thirds of men and nearly six in 10 women. In previous Democratic presidential primaries, Clinton has
carried a slight majority of women while Obama has enjoyed support
from slimmer majorities of males.

Over the weekend, Obama won Democratic contests in Louisiana, Washington state, Nebraska and Maine.

On the GOP side, despite exit polling that showed the Arizona senator struggling to win support with evangelical Christians and conservatives,
McCain will still collect 60 of Virginia's national convention delegates.

Heading into Tuesday, McCain already held a 3-to-1 advantage in Republican convention delegates.

Virginia voters could vote in either primary. In a twist, Huckabee was running slightly ahead of McCain among independents, who cast about a fifth of the Republican votes.

There are just over 100 delegates at stake in the three GOP races in Virginia, Maryland and the District of Columbia. It takes 1,191 delegates to clinch the Republican nomination, and McCain appears to be on track to reach the target by late April. Tuesday's wins put Obama ahead of Clinton in the Democratic delegate count for the first time.