I think that the editors of the NYTimes say it best:
Snator John Kerry goes toward the election with a base that is built more on opposition to George W. Bush than loyalty to his own candidacy. But over the last year we have come to know Mr. Kerry as more than just an alternative to the status quo. We like what we've seen. He has qualities that could be the basis for a great chief executive, not just a modest improvement on the incumbent.
We have been impressed with Mr. Kerry's wide knowledge and clear thinking - something that became more apparent once he was reined in by that two-minute debate light. He is blessedly willing to re-evaluate decisions when conditions change. And while Mr. Kerry's service in Vietnam was first over-promoted and then over-pilloried, his entire life has been devoted to public service, from the war to a series of elected offices. He strikes us, above all, as a man with a strong moral core.
There is no denying that this race is mainly about Mr. Bush's disastrous tenure. Nearly four years ago, after the Supreme Court awarded him the presidency, Mr. Bush came into office amid popular expectation that he would acknowledge his lack of a mandate by sticking close to the center. Instead, he turned the government over to the radical right...
...The Bush White House has always given us the worst aspects of the American right without any of the advantages. We get the radical goals but not the efficient management. The Department of Education's handling of the No Child Left Behind Act has been heavily politicized and inept. The Department of Homeland Security is famous for its useless alerts and its inability to distribute antiterrorism aid according to actual threats. Without providing enough troops to properly secure Iraq, the administration has managed to so strain the resources of our armed forces that the nation is unprepared to respond to a crisis anywhere else in the world.
Mr. Kerry has the capacity to do far, far better....We look back on the past four years with hearts nearly breaking, both for the lives unnecessarily lost and for the opportunities so casually wasted. Time and again, history invited George W. Bush to play a heroic role, and time and again he chose the wrong course. We believe that with John Kerry as president, the nation will do better.
Voting for president is a leap of faith. A candidate can explain his positions in minute detail and wind up governing with a hostile Congress that refuses to let him deliver. A disaster can upend the best-laid plans. All citizens can do is mix guesswork and hope, examining what the candidates have done in the past, their apparent priorities and their general character. It's on those three grounds that we enthusiastically endorse John Kerry for president.