Winning the big prizes of Florida and Texas and many of the Southern United States gave Clinton a sizable delegate lead.

Thus, Clinton initially retained an overall delegate lead following the Iowa results.

In a span of 11 days, he swept 11 contests and extended his pledged delegate lead by 120.

With little hope of overcoming Bush's delegate lead after Super Tuesday, McCain withdrew from the race on March 9, 2000.

Although his victories were not enough to end the race, they were enough to establish a two-to-one delegate lead over Santorum.

And Mr. Clinton has preserved his overwhelming delegate lead.

Clinton then lost the next eleven caucuses and primaries to Obama, and lost the overall delegate lead to him for the first time.

Obama won the next eleven February caucuses and primaries across the country, often by large margins, and took a significant pledged delegate lead over Clinton.

However, Stevenson's delegate lead was much too large for Harriman to overcome, and Stevenson won the nomination on the first ballot.

Although she did manage to win the majority of the remaining primaries and delegates, it was not enough to overcome Obama's substantial delegate lead.