By Jonathan Bernstein, Bloomberg News (TNS)

Surprise! It turns out Barack Obama supported marriage equality the whole time.

Well, not much of a surprise. Close political observers strongly suspected all along that he supported same-sex marriage. But advisers dissuaded him from taking that position in 2008, and he only chose to “evolve” on the issue going into 2012, when polling indicated his support would no longer be a liability.

What’s the sin here? I’m pro-hypocrisy. The ethics of politics don’t require politicians to take positions they “really” believe in. To the contrary: They are representatives, and what they owe their constituents is good representation. This begins (as the political scientist Richard Fenno understands it) with making promises during an initial campaign.

When those politicians govern, they make choices with those promises in mind, and then they explain their actions to constituents in terms of those promises. Eventually, they campaign for office again, and make a new set of promises, constrained and informed by what they said in the previous cycle.

It would have been a problem if Obama claimed to oppose same-sex marriage while intending to support it once he was elected. It wouldn’t have mattered if the broken promise was based on personal beliefs or on political considerations.

I see no evidence (so far) that Obama was guilty of such a violation. Instead, he gave weak support for his position in the 2008 campaign. And, while pure fiction, his subsequent story that his stance on same-sex marriage was “evolving” was nevertheless consistent with the obligation to explain his actions (in this case, his new position) in view of his original promises.

It’s true that Obama’s actions early in his presidency (before he supposedly evolved) had the effect of supporting marriage equality — in particular, selecting two Supreme Court justices likely to rule that way. But this, too, was consistent with the overall thrust of his 2008 promises, which were to be a liberal on social policy. One reason observers assumed Obama would flip his position as the polls changed was because his position on marriage was increasingly at odds with the rest of his stances on social issues.

Anyone looking for an area where Obama’s campaign promises haven’t matched his actions in office should focus on civil liberties. It’s no big deal when politicians conceal their private positions. It’s more serious when they don’t follow through on public promises and fail to explain the change.

Those promises might involve specific policies (such as opposing marriage equality), or they might be more amorphous commitments on how the politician will act in office — as a wonk, as a member of a demographic group, as an ideologue, or whatever else she promises. Note, for example, that Obama’s 2008 rhetoric emphasized his beliefs “as a Christian” while his 2012 public reversal also emphasized his (supposed) moral awakening on the issue, the place of “powerful traditions” and “religious beliefs” in the discussion, and how states moving on marriage had done a “good job in engaging the religious community.”

Photo: President Barack Obama speaks at a press conference in the East Room of the White House on Monday, Feb. 9, 2015 in Washington, D.C. (Olivier Douliery/Abaca Press/TNS)