US Democratic Senator for Illinois Barack Obama beat Sen. Hillary Rodham Clinton of New York in Tuesday's Mississippi primary as expected, but there is no end in sight to the neck-and-neck race between them.

As a result, Obama will collect a majority of the 33 delegates at stake in the state, but Clinton will also garner a share because the Democrats' way of delegate allocation is proportional, not winner-take-all.

Neither candidate is expected to clinch the sufficient number of delegates from nomination elections to win the nomination.

A prolonged, indecisive battle between Obama and Clinton will be a nightmare for Democrats, which have a good chance to win back the White House this year.

At the same time, Sen. John McCain of Arizona has already secured the Republican presidential nomination and will have enough time to figure out his way to fight either of the Democratic candidates in the November face-off.

The contest between Obama and Clinton also split the Democratic electorate, as exit polls showed in Mississippi.

Obama won the support of 91 percent of African American voters while Clinton won 72 percent of the state's white vote.

After Mississippi, the contest will go to Pennsylvania, where 158 delegates will be at stake on April 22.

However, that day won't break the current pattern of the Democratic race either.