But there were a lot of good reasons for the United States to establish relations with China. For one thing, China had a lot of people and was beginning to industrialize. Lots of people in an industrial country mean lots of customers for American goods. A strong trade relationship with the most populous country on Earth made (and continues to make) a great deal of economic sense.

But there were also political realities. By establishing ties with China, Nixon helped to coax our one-time enemy out of the Soviet sphere of influence, and, by doing so, effected a huge shift in the Cold War’s balance of power. He also assured that, through economic relations, the United States would influence China’s development into an industrialized nation.

It was the right thing to do. But it took somebody like Nixon — an ultra-conservative Cold Warrior with impeccable anti-communist credentials — to pull it off. Nobody else could have withstood the domestic pressure to treat China as a mortal enemy. Somebody had to do it, and Nixon was the right guy for the job.

announcement that President Obama will begin the process of normalizing relations with Cuba is a similar situation of an American president doing something that pretty much everybody knew had to be done but couldn’t do. But what qualifies Obama to go to Cuba is not his ideology, but his lame-duck status and his low approval ratings. He simply has nothing to lose.

America’s current embargo of Cuba makes no sense either ideologically or economically. The Cold War has been over for a quarter of a century. We have normal relations with communist countries like China and Vietnam — and with dozens of countries with records of human-rights abuses that make Cuba look like Disneyland. And we stand to gain tremendously by trading with one of our closest neighbors.

But anti-Castro Cuban exiles have a lot of political power, especially in Florida — which has a nasty history of deciding presidential elections by the slimmest of margins. And since the current tea party evolved directly from the John Birch Society, many of its largest donors still embrace an uncompromising anti-communist ideology as if it were still a thing.

The Cuban embargo has therefore been extended into a post-Cold War world where it is an embarrassingly irrational and counterproductive strategy that nobody was willing to risk the short-term political costs of doing anything about.

Except Obama. In his last two years in office, Barack Obama is politically unpressurable. He will never run for anything again. He has already lost the House and the Senate. And he knows that the current Congress will work tirelessly to frustrate and embarrass him in any way that they possibly can. And since a substantial portion of the country already believes that he is a Kenyan-born Muslim terrorist who drinks the blood of young children, being called "soft on communism" is just not that big of a deal. He has nothing to gain by avoiding controversy.

But nothing to gain is the same thing as nothing to lose—which is why only Obama can go to Cuba.