Delegate count:
Obama 1520, Clinton 1424
Needed to win: 2025
View photos of the campaign
KEY POINTS:
Three big wins gave Hillary Clinton's struggling Democrat campaign a big boost yesterday, and John McCain wrapped up the Republican nomination for the United States presidential election.
Senator Clinton vowed to go all the way to the White House after winning the Ohio, Texas and Rhode Island primaries, ending a hugely damaging 12-state winning streak by her rival, Barack Obama.
"For everyone who stumbled and stood right back up and for everyone who works hard and never gives up, this one is for you," she said.
Mrs Clinton, who had faced oblivion if she failed again yesterday, achieved a surprisingly solid 16-point victory in the bellwether state of Ohio, where polls had predicted a tight race.
She took Texas by 51 per cent to 47 per cent.
Mr Obama, who picked up the liberal state of Vermont, congratulated Mrs Clinton but pointed out that he had "nearly the same delegate lead as we had this morning, and we are on our way to winning this nomination".
Because the Democratic Party awards its delegates proportionally, Mrs Clinton needs a string of big wins to nullify Mr Obama's advantage.
Yesterday's wins mean she is likely to soldier on until at least the Pennsylvania primary on April 22.
After yesterday's votes, she had 1424 delegates to Mr Obama's 1520, according to CNN. A candidate needs 2025 delegates to win the nomination.
Both Democratic rivals will come under increasing fire from Senator McCain, who became the presumptive Republican nominee by passing the required delegate total of 1191 with a clean sweep in Texas, Ohio, Rhode Island and Vermont.
As Mr McCain reached the magic number, his rival, Mike Huckabee, dropped out of the race.
Mr McCain is expected to be formally endorsed by President George W. Bush today.
In his victory speech, Mr McCain, 71, challenged his rivals to explain how they would end the Iraq war without making it worse.
"The next president must explain how he or she intends to bring that war to the swiftest possible conclusion without exacerbating a sectarian conflict that could quickly descend into genocide, destabilising the entire Middle East," he said.
The war, the economy and energy independence were the areas he would focus on in his election campaign.
Mrs Clinton also mentioned the war as she pressed her case that she was the best person to lead the country, and again sought to hammer Mr Obama for his lack of experience.
"We have two wars abroad, we have a recession looming here at home. Voters faced a critical question. Who is tested and ready to be commander in chief on day one?"
The next states to vote in the Democratic contest are Wyoming on Saturday and Mississippi next Tuesday.
