Hillary Clinton made a stunning comeback in Tuesday's primaries and caucuses, winning decisively in Ohio and Rhode Island and coming out on top of a close race in Texas. John McCain won all four states, to clinch the Republican nomination, putting him in position to begin organizing for the November election, while his Democratic opponents continue to battle each other. VOA's Greg Flakus has more on the story from Houston.

After losing 11 straight contests to Barack Obama and being advised by some political pundits to drop out of the race, Hillary Clinton made a spectacular comeback on Tuesday, winning the popular vote in three of the four states holding primaries. Coming before cheering supporters in Ohio, she made it clear that she has no intention of quitting.

"You know what they say, as Ohio goes, so goes the nation. (cheers) Well, this nation is coming back and so is this campaign," she said.

Clinton also cast her gaze forward to the November election, presenting herself as the best candidate for the Democratic Party, based on her decisive win in Ohio.

"No candidate in recent history, Democrat or Republican, has won the White House without winning the Ohio primary," she said.

The other big winner of the evening was Republican John McCain, who beat challenger Mike Huckabee in all four states and clinched his party's nomination.

"Thank you, Texas, Ohio, Vermont and Rhode Island. Thank you," he said.

Huckabee congratulated McCain and announced his withdrawal from the race. McCain is now free to concentrate his time and money on preparing for the election in November. The decorated Vietnam War veteran will present himself as the more experienced candidate and the one who can best protect the nation from enemies abroad.

Clinton's recent campaigning included portrayals of her experience and good judgment and questions about the readiness of Barack Obama to be commander in chief. Obama responded by saying that she showed poor judgment when she voted in the Senate for the authorization to wage war in Iraq. Although he was not yet in the Senate at the time, he spoke out against the idea of going to war.

Speaking in San Antonio, Texas, after congratulating Clinton on her victories, Barack Obama concentrated his main rhetorical fire on John McCain.

"In this election, we will offer two very different visions of the America we see in the 21st Century, because John McCain may claim long history of straight talk and independent thinking and I respect that. But in this campaign he has fallen in line behind the very same policies that have ill served America," he said.

In the next few weeks there will be contests in small states, like Wyoming and Mississippi, where Obama is favored to win. The next large state battleground will be Pennsylvania, which holds its primary April 22. Clinton has strong support there, but she will be hard pressed to keep the momentum of her campaign going for the several weeks leading up to that contest. Obama holds a lead in delegates that will be difficult for Clinton to surpass. However, she could gain an edge among so-called super delegates before the Democratic convention in August. Party leaders hope the nomination can be decided long before that, so as not to give the Republicans the advantage of sitting on the sidelines while the Democrats continue to attack each other.