Writing at The Los Angeles Times, Professor Michael Klarman of the Harvard Law School argues that American presidents often do not get far ahead of public opinion on controversial matters — especially on matters of moral combat.

In making his case, Klarman argues that President Abraham Lincoln “was a relative latecomer to the abolitionist cause,” driven by Union losses on the battlefield to free the slaves. He argues further that Presidents Franklin Roosevelt, Harry Truman, and John F. Kennedy worked slowly on the issue of civil rights. Kennedy, he asserts, did not move to support civil rights within the first two years of his presidency because he needed the political support of conservative Democrats in order to achieve re-election.

Writing on “The Political Risks of Supporting Gay Rights,” Klarman explains that President Bill Clinton ran on a platform to eliminate the military’s “Don’t Ask, Don’t Tell” policy, but he was forced to compromise after facing opposition from the military and congressional leaders. President Barack Obama, he reports, ran on a platform to eliminate all discrimination against persons on the basis of sexual orientation but resisted any affirmation of same-sex marriage. Klarman attributes the President’s position to political necessity and polling.

In two very interesting paragraphs, he writes:

Public opinion on gay marriage has continued to evolve since 2004, when the nation opposed it by a margin of roughly 2 to 1. Most recent polls still show majority opposition, but the margin has shrunk to less than 10 percentage points. One well-respected statistician has estimated that by 2012 or 2013, a majority of people in a majority of states will support gay marriage.

Should Obama be reelected in 2012, he almost certainly will endorse gay marriage during his second term. By then, a majority of Americans, and an overwhelming majority of Democrats, will support the practice. Could Obama shift his position before 2012 without endangering his chances at a second term? Possibly.

Klarman’s analysis is interesting, but his prediction is fascinating. He openly predicts that President Obama “almost certainly will endorse gay marriage during his second term,” and he attributes the President’s current lack of open support for same-sex marriage to political necessity.

Klarman concludes:

But in many of the states that proved to be battlegrounds in the 2008 presidential campaign — Ohio, Indiana, North Carolina, Virginia, Florida — majorities still oppose same-sex marriage. A presidential pronouncement in favor would rally conservative opposition and could prove crucial to some swing voters. For many political progressives who believe that the issue already may have cost Democrats one presidential election (and, with it, two Supreme Court appointments), the risk isn’t worth taking.

We can only wonder: how many politicians on both the right and the left take their positions based on such a political calculation? Apparently, for far too many, the risk of telling the truth “isn’t worth taking.”