The U.S. presidential campaign sharpened last week with the withdrawals of Mr. Rudy Giuliani and Mr. John Edwards. Now, two main candidates dominate each race and will battle head to head in "Super Tuesday" this week and to their nominating conventions later this year. Voters in both parties now have the opportunity to put their choices side by side and measure their candidates and make informed decisions in November. America, and the world, benefit from this democratic pageant.

Mr. Giuliani, the former New York City mayor, was once the Republican front-runner. He faded by the time voters actually had to cast their ballots. Having put his future on the Florida results, his third-place finish finished his campaign. He withdrew and then endorsed Arizona Sen. John McCain. That aids Mr. McCain in his fight against former Massachusetts Gov. Mitt Romney, although former Arkansas Gov. Mike Huckabee continues to fight, despite limited money and limited appeal beyond Christian conservatives.

Mr. Edwards, a former senator and the running mate of Democratic nominee Sen. John Kerry in 2004, withdrew after it became clear that he was destined to play — at best — the role of spoiler. He has not endorsed a candidate and polls show his supporters split between the two remaining candidates, Sen. Hillary Clinton and Sen. Barack Obama. The delegates he won in the earlier caucuses go into the undecided pool. Most significantly, Mr. Edwards' withdrawal means that for the first time in history either a black man or a woman will head the ticket of one of the major parties in the U.S. election.