Barack Obama and Hillary Clinton will continue their battle for the Democratic Party's presidential nomination for several weeks to come after the latest contests proved indecisive.
Mr Obama again failed to end the former First Lady's presidential aspirations in the 2008 White House race and she emerged as the night's winner, dedicating her victory in Ohio to "anyone who's ever been counted out but refused to be knocked out".
But while the results may keep Mrs Clinton in the race for the moment, they are unlikely to have any significant effect on the gap between the two rivals in the number of delegates who support them.
Instead, the Republican Party and John McCain, who will now be endorsed by President George Bush at the White House, will focus entirely on November's general election while the Democrats are still fighting among themselves.
Senior Democratic Party officials have expressed concerns that this could undercut the party's chances of taking the White House.
Mrs Clinton's comeback after losing 11 consecutive contests to Mr Obama will re-open the race and the two presidential hopefuls will move on to the next contests in Wyoming and Mississippi, and then on to Pennsylvania in seven weeks' time, in a very similar position.
But today's victories will fuel the Clinton campaign's claims that the former First Lady wins the larger, so-called battleground states which will be crucial in the general election.
And it will also halt Mr Obama's momentum gained from a successful month for his campaign in February.
But the intense arguments between Mr Obama and Mrs Clinton over the past four days look set to continue.
Mrs Clinton said her campaign was just getting "warmed up" but Mr Obama said the New York senator had employed a "kitchen sink strategy" as she made a final bid to revive her presidential prospects.
Mrs Clinton suggested that the young Illinois senator had been dishonest in his handling of the North America Free Trade Agreement (Nafta), that he was too inexperienced to be president, and that he would need a "foreign policy instruction manual" to keep America safe.
But Mr Obama has said he does not want to run a negative campaign, choosing instead to address criticism of his foreign policy experience and his message of change and hope for America in his speech to supporters in Texas.
He said he would not substitute "bluster and bullying" for diplomacy as Mr Obama referred to criticism of his plans to sit down for talks with the leaders of Iran and Cuba as president.
"Strong countries and strong leaders aren't afraid to tell hard truths to petty dictators," he said.
And he added that his call for change, which has been dismissed by both Mr McCain and Mrs Clinton as "eloquent but empty, speeches not solutions", had first come from Americans across the nation.
Mr Obama also failed to end his rival's presidential hopes in New Hampshire when she achieved a surprise win, despite a devastating defeat just five days earlier in Iowa, following a teary moment on the campaign trail.
And now Mrs Clinton's tactics of taking the fight to Mr Obama, putting him under pressure from both his rivals and the media, appears to have worked effectively, especially with Mr Obama's stated reluctance to engage in negative campaigning.
He will need to find a way to tackle the challenges thrown at him by the Clinton campaign if he is going to succeed in the race, which has now opened up and is set to last for weeks to come.Reuse content