Romney and Obama never went out of bounds. In fact, on some topics, they never even came close.
Now that the candidates have left the hustings (whatever those are) behind, it can be said: This was the cleanest presidential campaign in recent memory, perhaps in American history.
Before you get exercised about Mitt Romney's sketchy tax math or President Obama's attacks on Bain Capital Partners, take a deep breath and look at the evidence. If you can step outside your preference for your own candidate, you will see a good, clean, hard fight -- one focused overwhelmingly on the issues and informed by the fundamentally decent competitive impulses of the candidates. Both wanted very much to win, but neither was willing to ride dirty to get there.
Start with character. For the first time in decades, no candidate insinuated or allowed his supporters to insinuate that the other candidate was fundamentally fraudulent. There was no swift-boating, and other than Donald Trump and a handful of other attention-seekers and fringe conspiracy-mongers, there were no "birthers" darkly hinting that one candidate was Manchurian.
Yes, Obama pointed to Romney's flip-flopping and suggested that he had no core principles, but that was very different from alleging that Romney had concocted his past out of whole cloth. Some pro-Romney ads depicted Obama as a self-loving celebrity, but this was a legitimate line of attack against a president who received the Nobel Peace Prize just for showing up.
Then there's religion. Remember that issue? It's not only that neither candidate insisted God was on his side and his side only, in the way George W. Bush managed to suggest in two different elections. No, this was a race between the two most religiously outré candidates in U.S. history, offering nearly infinite opportunity for a faith war. Yet it never came.
Four years ago, commentators (myself included) wondered seriously whether the public would ever accept a Mormon president. Yet the Obama campaign did not emit even the most subtle hints about Mormonism's polygamist past or its outlying present beliefs and practices. When was the last time you heard somebody talking about Mormon garments, an irrelevant topic that nonetheless came up repeatedly in the 2008 primaries?
Nor was there any attempt to invoke the (noncanonical) White Horse Prophecy associated with Joseph Smith, which predicted that the U.S. Constitution would someday be saved by a heroic "white horse" associated with the Church of Jesus Christ of Latter Day Saints.
Mitt Romney deserves equal credit for saying exactly nothing about Obama's former pastor Jeremiah Wright, an intellectual inheritor of black liberation theology. Romney also distanced himself from even subtle implications about Barack Hussein Obama's Muslim family background or his childhood in Indonesia. He refused to tap into growing anti-Muslim sentiment in the heartland that can be seen in proposals for preposterous anti-sharia laws in several states.
A cynic could plausibly claim that religion was a potentially radioactive topic for both candidates, dismissing their discretion as nothing more than self-preservation. I don't buy it: Each side could reasonably have calculated that it had more to gain from subtle religious aspersions than it had to lose.
A much more probable explanation is that Romney and Obama, both buffeted in the past by illegitimate religious sentiments, were genuinely unwilling to use bigotry as a weapon. Besides, the combination of self-interest and principle is the base on which religious tolerance was built in the West. It is to be admired, not disparaged.
What about the White House's insistence that Romney was lying about the president's record, or Romney's displeasure that Obama attributed to him the private sorrows of individuals who lost their jobs after Bain Capital acquired their employers? The short answer is that such distortions are part of the altogether permissible political game of dramatic overstatement and policy imprecision.
Sure, Romney wasn't exactly telling the truth when he accused Obama of "apologizing" to the world. But it was true that Obama came to office with the express strategy of reassuring America's allies that he wasn't Bush, and that the swashbuckling, "time of our choosing" nightmare of foreign-policy disasters was over. Any democratically elected politician in any country on Earth would be inclined to characterize this stance as "apologetic" to win votes.
A pro-Obama ad (not produced by the campaign) that told a heartbreaking story of a woman's fatal cancer after her husband lost his job in a Bain Capital firing was also not, strictly speaking, true. (It turned out that five years had elapsed, and that she had her own health insurance from a separate job until that job disappeared.) But the point of the ad was to suggest that a man who got rich acquiring firms and resizing them for resale was not likely to feel sympathy for those who became unemployed as a result.
Show me a politician who would not take this approach against a private-equity millionaire, and I'll show you a person who couldn't win an election for dogcatcher. People in finance and private equity may feel personally offended by the ad, but that is because they aren't running for anything.
In the 1800 presidential election, John Adams's supporters said that Thomas Jefferson was an atheist who was having an affair with his slave, Sally Hemings. Of course, both of these charges were more or less true.
But that isn't the point: Mudslinging of the personal, character-assassination type is a longstanding and persistent feature of our electoral politics. This time around, however, two basically decent men took the high road. In this highly polarized, highly partisan moment in our political history, we should allow ourselves a moment to appreciate just how impressive this really was.
Noah Feldman, a law professor at Harvard University and the author of "Scorpions: The Battles and Triumphs of FDR's Great Supreme Court Justices," is a Bloomberg View columnist.