Gil Troy, professor of history at McGill University, is the editor, with Arthur Schlesinger Jr. and Fred Israel, of “History of American Presidential Elections, 1789-2008,” fourth edition, just released by Facts on File of Infobase Publishing.

There we go again. After nonstop headlines a year before Election Day and nine debates between the Republican candidates (number 10 is scheduled to take place on Wednesday in Michigan), Americans are already grumbling that the 2012 presidential campaign is ugly and interminable. But these quadrennial complaints about campaigning miss the point.  Presidential campaigns are nasty, long and expensive because they should be. Many aspects of campaigns that Americans hate reflect democratic ideals we love.

The presidential campaign’s length and fury are proportional to the electorate’s size and the presidency’s importance.  A new president should undergo a rigorous, countrywide, marathon job interview. Citizens need time to scrutinize the candidates. As David Axelrod, Barack Obama’s senior strategist, puts it: “Campaigns are like an MRI for the soul, whoever you are eventually people find out.” Already this year, “easy favorites” like Tim Pawlenty fizzled, while Rick Perry learned that years governing Texas do not provide as much political seasoning as weeks of presidential campaigning. Mitt Romney, his aides admit, worked out his campaigning “kinks” in 2008.  That year, Sarah Palin’s popularity waned while Barack Obama’s soared, the more each campaigned.

These nationwide courting rituals should be long enough to let great politicians flourish and bond with the nation. John F. Kennedy became a better president and person by encountering Appalachian poverty during the 1960 West Virginia Democratic primary. During his 18,009 mile, 600-speech campaign in 1896, the Populist Democrat William Jennings Bryan insisted that voters “have a right to know where I stand on public questions.” Franklin D. Roosevelt’s strategist advised his candidate in 1932 in strikingly modern terms: “You are you,” he said, and “have the faculty of making friends on a campaign tour.” Traditionally, candidates repeated stump speeches so frequently that, as Herbert Hoover noted, “paragraphs could be polished up, epigrams used again and again, and eloquence invented by repeated tryouts.”...