-- This is the first time the Democrats have come to Massachusetts for their convention, but not the first time they have found their candidate here. Twice before in modern times, in 1960 and in 1988, they have offered sons of Boston to the country -- with startlingly different results. Now they are here to nominate John F. Kerry, yet another striver who cut his eyeteeth in Bay State politics.

In 1960 John F. Kennedy won an upset victory over Vice President Richard M. Nixon. In 1988 Michael S. Dukakis lost a race he was expected to win against Vice President George H.W. Bush. Kerry faces far different circumstances than they did, and those differences help define the challenge he now confronts.

Kennedy was a moderate to conservative senator with formidable campaign skills but few legislative accomplishments when he set out to succeed the widely admired Dwight D. Eisenhower.

Both his youth -- he was 43 at the time of the campaign -- and his Roman Catholic religion were seen as barriers to his election. But he used the first televised presidential debates to demonstrate that he was at least Nixon's equal in maturity and aplomb. And he skillfully defused the religious issue by confronting it in a dramatic session with the Houston Ministerial Association, where he satisfied skeptics that he would not accept dictation from Rome, while avoiding offending his fellow Catholics.

Kennedy carefully sidestepped any direct criticism of the popular Eisenhower and benefited from Democratic antipathy to Nixon. By selecting his most plausible rival for the presidential nomination -- Lyndon B. Johnson -- as his running mate, he avoided a serious sectional split in the party and enabled the ticket to compete successfully for Texas and states in the South.

Kerry shares Kennedy's initials and his status as a decorated Navy combat veteran -- but not much else. At 60, he is a seasoned political leader with a record that places him in the mainstream of his party. He is no match for Kennedy on the stump, but neither does he face the religious prejudice that confronted Kennedy. As far as I can judge, Kerry's Catholicism is irrelevant to most voters.

Bush has come close to Nixonian standards as a target for Democratic disdain, and the affection for his father is not at Eisenhower levels, so it hardly serves to cushion the opposition blows. Eisenhower and Nixon had ended a war in Korea and held the line against Soviet communism. Bush has won military victories in Afghanistan and Iraq but has not been able to bring the troops home from either nation.

Kerry, like Kennedy, went south for a running mate and picked his leading rival. But John Edwards of North Carolina is not the political heavyweight Johnson was -- and the South is a far tougher target for Democrats now than it was then. The dynamics of this race will be very different from 1960. California, Nixon's home state, is now the Democratic base.

Kerry has more in common with Dukakis, for whom he served as lieutenant governor for two years before coming to the Senate. Dukakis was a classic reform-minded suburban politician, with a liberal profile that Kerry shares on social issues such as the death penalty. His relations as governor with Boston's Irish pols were even more distant than Kerry's, but neither man has had a reputation for being easy company or a lot of laughs.

Dukakis had to labor much longer than Kerry did to win the nomination; he finished third in the leadoff Iowa caucuses, where Kerry won his first and ultimately most important victory. And Dukakis was still struggling at his nominating convention to settle matters with Jesse L. Jackson, while Kerry is certain to be embraced by all factions of the party.

The real advantage Kerry has is the lesson taught by Dukakis's defeat: Don't be passive in the face of Republican attacks. Dukakis let the first George Bush's campaign paint him as an elitist out of touch with basic American values, because the governor believed that his immigrant roots and spartan lifestyle would be enough to disprove the charge. He never recovered.

Kerry plainly has taken the message to heart. As in 1988, the president's men have repeatedly questioned the Democrat's values, but no attack on Kerry's record or his personal traits has gone unanswered for more than a few hours.

The vigorous counterpunching has kept him even with the incumbent in the polls, but has yet to solidify any sort of lead for Kerry. That task still awaits him as the convention begins.

davidbroder@washpost.com