Lexington: A tilted playing field NOW the campaign can really begin. Almost every week lately, and especially since it became clear that Mitt Romney would after all be the Republican nominee, some such story has appeared in some news outlet. The pretext this week was the brace of formal campaign events Barack Obama was due to hold in Ohio and Virginia on May 5th. Informally, however, the president has been campaigning for re-election for months - if not, as some would say, from the day he was elected in 2008. This is now attracting new attention to the so-called "incumbency advantage" in presidential elections. In general American voters are obliging towards presidents who seek a second term. Of the previous eight presidents who got their job by election (ie, excluding Lyndon Johnson and Gerald Ford), all bar the senior George Bush and Jimmy Carter won second terms. Perhaps voters think it only fair, other things equal, to give a president his full eight-year maximum. But an incumbent also benefits from many advantages which, or so challengers say, tilt the playing field and make for an unfair fight. These advantages range from the broad and ephemeral (command of the bully pulpit) to obvious perks such as the use of Air Force One, the flying presidential command post and mother of all status symbols. The use and abuse of the big Boeing is a subject of perennial contention during election campaigns. In theory, the president is entitled to use it at taxpayers" expense only when he is on official business. His campaign is required to reimburse the government for whatever portion of a trip is devoted to electioneering. But how do you tell the difference? It is next to impossible. In April Reince Priebus, the chairman of the Republican National Committee, wrote to the comptroller-general accusing Mr Obama of passing campaign travel off as official events. Mr Priebus complained in particular about the president's visits to North Carolina and Colorado, both battleground states, where he gave speeches "to cheering crowds of college students, events widely reported to be equivalent to campaign rallies." The bland response from a White House spokesman was that these trips were "part of the president's official responsibility to get outside of Washington, DC, hear from students, and discuss stopping interest rates on their loans from doubling." Good luck to the lawyer who tries to sort out such distinctions. Political scientists have it somewhat easier. Some try to tell whether Mr Obama is stretching his definition of official business by measuring whether he devotes "disproportionate attention" to battleground states. Like others before him, he does. A forthcoming book, "The Rise of the President's Permanent Campaign," has excited some of the president's critics. It reports that by June 2011 about half of Mr Obama's travelling days had been spent in key electoral states containing just over a third of the population (the study excludes Maryland and Virginia, adjacent to Washington, DC). Indeed, within just over four months of being sworn in, Mr Obama visited 14 states, of which only three were safely Democratic. The same book finds that Mr Obama has conducted more fund-raisers than previous presidents. But its author, Brendan Doherty of the United States Naval Academy, is careful to put all this in the context of the "permanent campaign" that has flavoured most modern presidencies. Mr Obama is the latest in an escalating series of fund-raising presidents, says Mr Doherty, not an outlier. The incumbency advantage is also the issue in the flap this anniversary week over how much credit Mr Obama should claim for ordering America's navy SEALs into Pakistan to kill Osama bin Laden. His secret dash to Afghanistan and speech from the Bagram airbase (speaking at 4am local time in order to hit prime-time TV back home) suggests that Mr Obama has decided to squeeze every ounce of electoral advantage from it. He has enlisted Bill Clinton as a praise-singer in a new video. You hire a president to make the toughest calls, Mr Clinton tells the camera; and as "decider-in-chief," Mr Obama got it just right. What if bin Laden had not in fact been at the compound? Or if some of the SEALs had been captured or killed? The downside would have been "horrible." Text then splashes across the screen asking what Mr Romney would have done. In 2007, after all, he criticised then-candidate Obama for vowing to strike al-Qaeda in Pakistan if necessary. He also said back then, "It's not worth moving heaven and earth and spending billions of dollars just trying to catch one person." The Republicans are crying foul. Any occupant of the Oval Office would have given the same order, they maintain; Mr Obama is taking credit for happening to be the incumbent when the manhunt initiated by his predecessor finally came good. Why, "Even Jimmy Carter would have given that order," said Mr Romney. There's a downside, too In a country that reveres its armed forces, it certainly does not hurt to be campaigning as commander-in-chief, with all the pomp and gravity that title entails. But this is small compensation for defending a job whose powers in the realm of domestic policy are wholly unequal to voters" expectations. And the advantage of being commander-in-chief turns into a liability the instant things go wrong. When Mr Romney says that "even" Mr Carter would have ordered the killing of bin Laden, he implies that Mr Carter was a wimp. That is hardly fair. Gore Vidal once called America the United States of Amnesia. But Mr Romney surely remembers that Mr Carter's electoral fate was in fact sealed when he gave the order for a rescue mission to pluck America's embassy hostages from the heart of Tehran. That was a much more daring gamble than Mr Obama's, and it failed. Incumbency has its risks and costs, as well as its many advantages.