"America's mayor" Rudy Giuliani has given Republican front-runner John McCain his support for the party's presidential nomination.

The former New York mayor pulled out of the race after his campaign tactics of focusing on Florida and ignoring early states backfired with a disappointing result in the state's primary election on Tuesday night.

Arizona senator Mr McCain now heads to next week's Super Tuesday, when more than 20 states will go to the polls.

Mr Giuliani's announcement came just hours after Democrat John Edwards officially pulled out of the race for the White House.

The Former North Carolina Senator has not won any contests in the race for the Democratic nomination for the November election and has lagged behind front-runners Barack Obama and Hillary Clinton in public opinion polls.

"It's time for me to step aside so that history can blaze its path," the 54-year-old told supporters in New Orleans.

Mr Edwards did not endorse either of his rivals.

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