Democrats Fight on for Nomination, McCain Seals GOP Spot

	Hillary Clinton, speaking to supporters in Columbus, Ohio, won a campaign-saving victory in that state Tuesday.

Hillary Clinton, facing a do-or-die test, scored a critical victory in Ohio Tuesday night and fought a close battle in Texas that cut into Barack Obama's lead in the race for delegates to the Democratic convention.

"They call Ohio a bellwether state. It's a battleground state. It's a state that knows how to pick a president," Clinton said at a boisterous rally in Ohio Tuesday night. "No candidate in recent history has won the White House without winning the Ohio primary."

Clinton, who had seen her core voters slipping away in a recent spate of contests, garnered widespread support from lower wage earners, union members, white women and voters who were concerned about the economy.

The candidates split the results in smaller contests, with the New York senator winning in Rhode Island and Obama scoring a victory in Vermont.

Clinton won the popular vote in Texas, but because that state has a complicated two-part primary-caucus system, the number of delegates awarded was very close.

McCain wraps up Republican nomination

	After sticking in the race against impossible odds, former Arkansas Governor Mike Huckabee dropped out of the Republican primary Tuesday night.

McCain's last remaining major rival, former Arkansas Governor Mike Huckabee, made good on his promise to drop out of the race when another candidate reached the nomination-clinching 1,191-delegate mark.

"Our campaign must be -- and will be -- more than another tired debate of false promises, empty sound-bites, or useless arguments from the past that address not a single American's concerns for their family's security," McCain told supporters in Texas Tuesday night.

For McCain, success came on his second try for the White House. He lost the GOP nomination to President Bush in 2000 after being derailed in South Carolina -- a state that helped propel him to the front of the GOP pack this election year.

He managed to stave off the more conservative Huckabee, the better-funded Massachusetts Governor Mitt Romney, the television star and former Senator Fred Thompson and former New York City Mayor Rudy Giuliani -- known internationally from his leadership after Sept. 11.

What's ahead

	Despite losing three of four contests Tuesday, Barack Obama maintains a large delegate lead over Hillary Clinton.

"No matter what happens tonight, we have nearly the same delegate lead as we did this morning, and we are on our way to winning this nomination," Obama told supporters in Texas.

Even before the first results began to trickle in, the Obama team was outlining the basic math problem underlying the Clinton candidacy.

According to forecasts in the remaining 10 states still to vote, the Obama campaign and most analysts expect that unless Clinton is able to decisively win in all of those contests, she would remain behind Obama in pledged delegates through the remainder of the race.

If those projections hold up, the Democratic nomination would come down to super delegates - around 800 high ranking party officials who can vote as they please -- and a legal battle over whether to count the Florida and Michigan contests, which were officially disqualified after the states moved up their primary dates against national party orders.

In a campaign that has seen some 40 states vote in the first eight weeks, analysts point to the April 22 contest in Pennsylvania, with its 158 delegates, as the next major test for the campaigns -- posing new challenges for both campaigns as they shift from the breathless sprint of recent contests to a long-term war of attrition for their party's nomination.