For Scott Brown, a Third Round in the Battle Against Partisan Gravity In 2010, Scott Brown became the first Republican elected to represent Massachusetts in the United States Senate since Edward Brooke in 1972. Mr. Brown's victory, in a special election for the seat formerly held by Edward M. Kennedy, was full of substantive and symbolic significance, costing Democrats their 60-seat Senate majority and threatening the passage of the national health care bill that Mr. Kennedy had once championed. But this November, Mr. Brown was the only incumbent senator to lose his general election bid, falling to Elizabeth Warren by seven percentage points. Another incumbent, Richard G. Lugar of Indiana, lost in the Republican primary. Mr. Brown may soon get a third opportunity to overcome the odds that any Republican faces when running for federal office in Massachusetts. If President Obama names Senator John Kerry to be his secretary of state, and Mr. Kerry is confirmed by the Senate, then Massachusetts will hold a special election in summer 2013 to fill out the remaining year and a half of Mr. Kerry's term. Whoever wins the special election would then stand for election to a full six-year term in November 2014. Mr. Brown has not yet officially confirmed his interest in the Senate race. There is a chance that he could run instead for governor, an office that has historically given Massachusetts Republicans better chances of success. Massachusetts voters elected Republicans as governor for four consecutive terms from 1990 through 2002, before the Democrat Deval Patrick won office in 2006. But a poll released on Thursday provided encouraging news to Mr. Brown. The survey, conducted by The MassINC Polling Group for WBUR, found Mr. Brown leading a series of potential Democratic opponents for the Senate seat by margins ranging from seven percentage points (against Mr. Patrick) to 27 (against Representative Stephen Lynch). Polls conducted this early in an election cycle are often tests of name recognition as much as anything and need to be evaluated carefully for that reason. But in Mr. Brown's case, it is not just that Massachusetts voters know him: they also like him. In the poll, 58 percent of voters said they had a favorable view of Mr. Brown, and 28 percent an unfavorable one. And yet there is this quandary: if Mr. Brown is so popular, how did he lose his re-election bid last month? The exit poll from this year's Senate race provides plenty of hints as to why. Sixty percent of Election Day voters said they had a favorable opinion of Mr. Brown -- but almost one-quarter of those voters chose Ms. Warren anyway. For a candidate to lose an election despite a 60 percent favorability rating, at least one of two things must be true. Either the voters like his opponent even better -- or they like the candidate as a person, but have too many policy disagreements with him. The answer could determine if Mr. Brown is a favorite or an underdog should he decide to run for the Senate again. If voters saw something extraordinary in Ms. Warren, then Mr. Brown might be expected to prevail against a more mediocre opponent, as he did in 2010 against the Democratic attorney general, Martha Coakley. If instead it was something more intrinsic to the problem that any Republican faces in Massachusetts, then even a lesser-known Democrat could potentially catch up to and surpass Mr. Brown in the polls, as Ms. Warren did. Ms. Warren, indeed, had trailed Mr. Brown by 17 points in the first poll conducted of their match-up in March 2011 -- a deficit similar to the one that Mr. Brown's potential Democratic opponents face in the WBUR poll now. Although Ms. Warren commands enthusiastic support from some Democrats in Massachusetts and elsewhere for her vigorous defenses of liberalism, and raised an incredible $41 million in individual contributions, she also had some flaws as a candidate. Having never run for office, Ms. Warren stumbled at times early in the race, embroiling herself in a controversy about how she had represented her Native American heritage. Ms. Warren's favorability rating -- 56 percent among Election Day voters -- was perfectly adequate but not extraordinary, and was slightly worse than Mr. Brown's. And 37 percent of voters said they thought Ms. Warren was too liberal, even in Massachusetts. In the exit poll, 34 percent of voters said Mr. Brown was too conservative. But such is the intrinsic advantage that Democrats hold in Massachusetts that Ms. Warren won the election despite having the support of only about 4 in 10 independent voters. For a Democrat to lose in Massachusetts, she must perform even worse than this -- as Ms. Coakley did in 2010, when she carried only 21 percent of the independent vote. A "generic" Democrat who avoided the mistakes that Ms. Coakley made (like insulting the former Boston Red Sox star pitcher, Curt Schilling) would thus seem to stand a reasonably good chance against Mr. Brown. There are other circumstances, however, that could work in Mr. Brown's favor. Most important is the abbreviated timing of the special election. There was no one moment at which Ms. Warren suddenly leapt ahead of Mr. Brown in the polls. Instead, she slowly wore him down over a campaign that lasted for almost 14 months, overcoming her initial errors to return the focus to Mr. Brown's policy positions. In a special election campaign that lasted only a few months, the Democratic candidate would not have that luxury. And because the Democratic nominee will probably face a competitive primary, while Mr. Brown probably will not, that would give the Democratic nominee even less time to focus on the general election campaign. Ordinarily, it is an advantage for a candidate to run as an incumbent -- but Mr. Brown could potentially benefit from not having to take difficult votes in the Senate and instead drawing more distance between himself and national Republicans. This week, he stated his support for a ban on assault weapons, breaking with Republican orthodoxy. The overall political environment is not likely to be as favorable for Democrats in the special elections as it was this November (although it will probably also not be so unfavorable to them as in 2010). And there could be an element of sympathy for Mr. Brown among some swing voters: this is a man they like reasonably well. Are they willing to reject him twice in the span of less than a year? Despite all that, it is difficult to view Mr. Brown as much better than even money: he is a Republican in Massachusetts who lost an election by a reasonably clear margin just last month. And if Mr. Brown wins, he could well face another competitive election in November 2014, when Democrats will have more chance to gear up from the race - and when Mr. Patrick will have finished his second term as governor and might be more likely to run for the Senate. One thing is for certain: if Mr. Brown is the senator from Massachusetts in January 2015, he will have earned it, having run for office four times in less than five years.