Obama set to overtake Clinton as Democrats' front-runner

Barack Obama said he was tough enough to lift America up and out of a period of divisive and ineffective government today as he looks set to overtake Hillary Clinton in the race for delegates.

A clean sweep of the weekend’s four election contests left him virtually tied with the former First Lady – with one estimate, by independent website RealClearPolitics.com, even putting him five delegates ahead.

Tomorrow’s so-called “Potomac” primary elections in Virginia, Maryland and the District of Columbia, where Mr Obama is expected to do well, will be crucial if his campaign is to build the momentum needed to stop Mrs Clinton surging ahead in next month’s contests in Texas, Ohio and Pennsylvania.

On the campaign trail in Maryland today, he told more than 15,000 people at the University of Maryland that he decided to run for president because of issues such as the Iraq war, global warming and the economy.

“I was convinced that the size of these challenges had outstripped the capacity of a broken and divided politics to solve,” he said.

The 46-year-old Illinois senator said America “wanted a politics that wasn’t about tearing the country down, but was about lifting the country up”.

“We need something new,” he said.

He also dismissed Mrs Clinton’s suggestions that he was not tough enough to handle the presidency, saying: “I may be skinny, but I’m tough too.”

Mr Obama, who enjoys success among African-American voters according to exit polls, is expected to perform well in the Potomac primary tomorrow, where all three states have a significant African-American population.

Mr Obama won the Democratic contests in Louisiana, Nebraska, Washington state and Maine at the weekend – and picked up a Grammy for the audio version of his book, The Audacity Of Hope, beating former President Bill Clinton in the process.

But Mrs Clinton’s weekend saw her change her campaign manager, Patti Solis Doyle, at a critical moment in the race.

She was replaced by Maggie Williams, who has worked with the New York senator for more than a decade. Ms Doyle will remain as a senior advisor to the campaign, and no reason for the change was given.

In the race to win the support of 2,025 delegates – the magic number of delegates needed to officially secure the Democratic Party’s nomination at the convention this summer – an AP estimate puts Mrs Clinton with 1,136 against Mr Obama’s 1,108.

CNN’s estimate also shows Mrs Clinton with a slim lead – 1,148 to 1,121 – while RealClearPolitics.com shows Mr Obama edging ahead, with 1,143 compared to 1,138.