Campaigns Will Seek to Define Romney There is no good time for a presidential candidate to face what Mitt Romney faced last week, when The Washington Post reported that he had tormented a fellow student while at prep school in the 1960s. But the months between the end of the primary season and the formal start of the general election at the conventions are an especially perilous period for candidates in Mr. Romney's position. It is then that challengers to an incumbent are most susceptible to being defined on terms other than their own, because despite months on the campaign trail they are still not yet terribly well-known by many Americans. Unflattering characteristics, new elements of their record, gaffes and embarrassing biographical details - all can take on outsize importance as rival campaigns labor through the spring and summer to create perceptions that stick with voters through Election Day. The Obama campaign stepped up its efforts on that front on Monday with a new ad portraying Mr. Romney as a job killer during his years running Bain Capital. It may be weeks or months before it is clear whether the image of Mr. Romney as youthful bully nearly a half-century ago puts an emotional punctuation mark on Democratic efforts to portray him as elitist and out of touch, or is swept away in the rush of other campaign developments and more contemporary issues. Even before the prep school story emerged, more Americans judged Mr. Romney unfavorably than favorably, according to the New York Times/CBS News poll, and perceptions of him are up for grabs among the more than a third of the country that does not yet have an opinion. As a result, Mr. Romney faces intense pressure to widen his appeal and lock in a more positive impression before the Obama campaign defines him on its terms. The risks of failing to win the spring-summer narrative battle are substantial. Just ask Michael Dukakis, Bob Dole or John Kerry, all of whom failed to establish strong positive images during this period and allowed their opponents to brand them in ways they never overcame. In 1988, Vice President George Bush used Willie Horton starting in June to portray Mr. Dukakis, the Democratic nominee that year, as a soft-on-crime liberal. Mr. Dukakis never really found a way to respond, and was wiped out in November. In the spring of 1996, President Bill Clinton's team portrayed Mr. Dole as old and a tool of radical conservatives in Congress like Newt Gingrich. Mr. Dole desperately tried to establish a fresh identity for himself by resigning from the Senate in May, but could not establish a consistent case for his candidacy and was drubbed in the fall. In 2004, President George W. Bush's campaign seized on a statement made by Mr. Kerry as he was wrapping up the Democratic nomination in March - "I actually did vote for the $87 billion before I voted against it" - to portray him as a flip-flopper, a characterization that Mr. Kerry never shed. Combined with the attack on Mr. Kerry's military record later that summer by the Swift Boat Veterans for Truth, the flip-flop attacks helped provide Mr. Bush with his slim margin of victory. Mr. Dukakis, Mr. Dole and Mr. Kerry shared a problem beyond the facts of their own records and statements: as they shifted into the general election after the primaries, they had not yet established favorable identities for themselves among voters. Mr. Kerry was viewed unfavorably right after the end of the primary season in 2004 by about the same number of Americans who viewed him favorably; perhaps more importantly, fully half the country was undecided about him, making him something of a blank slate for Mr. Bush's team to fill in. Mr. Dole consistently had negative favorable/unfavorable poll ratings, with more than a third of the country undecided about him through the spring and summer of 1996. He never won over enough of them to be competitive with Mr. Clinton. Mr. Dukakis had reasonably strong poll numbers as he wrapped up the Democratic nomination in 1988 - he was judged favorably by 38 percent in May and unfavorably by 14 percent - but like Mr. Kerry 16 years later, half the country was undecided about him. Within months, as Republicans pushed Willie Horton and other attacks, those undecided voters broke overwhelmingly for Mr. Bush. Winning candidates, by contrast, tend to reach late spring with at least as many people judging them favorably as unfavorably and to show quick progress in winning over undecideds. As Mr. Obama finally wrapped up the Democratic nomination in late spring of 2008, he was viewed favorably by 41 percent of Americans and unfavorably by 31 percent, with 27 percent undecided; by October he had pushed his favorability rating over 50 percent. In 2000, both George W. Bush and Al Gore drove their favorability numbers higher during the period, setting up a battle that continued past Election Day. The preconvention perception battle is especially intense this year. The conventions are late (the Democrats will not wrap up until after Labor Day), meaning the formal general election season will be relatively short. Early voting effectively shortens it even more in many places; voters in many states will start casting ballots in early October, making the final weeks of the campaign moot for them. And with three presidential debates and one vice presidential debate scheduled for October, the candidates will find it harder to control the message in the campaign's closing stages. All of which helps explain why both the Obama and Romney campaigns are so eager to get back on message this week. Mr. Obama's roll-out of his general election message last week was squashed when he was forced into taking a clear position on gay marriage. Mr. Romney, despite having been running for president more or less consistently since 2007, found his biographical narrative at risk of being altered in an unflattering way by a single news story. Both candidates have experienced and hard-hitting campaign teams, and their relative success in taking control of the candidates" images in the next month or two could go a long way toward determining what happens on Nov. 6. Allison Kopicki contributed reporting.