<p>It is safe to say that if John Kerry had lost his Senate re-election bid to Republican Gov. William Weld in 1996, Mr. Kerry would not be the Democrats' presumptive presidential nominee today. Mr. Weld, who won re-election as governor in 1994 with 71 percent of the vote, was a formidable opponent. In a novel arrangement, both candidates pledged to limit the use of their families' personal wealth to $500,000 for the general election.</p>