President Obama spoke Friday about the terrorism attack in France. (AP Photo/Carolyn Kaster)

President Obama is being slammed for not attending Sunday’s huge Paris rally in response to last week’s terrorism in France. The White House has suggested that security issues made the participation of the president and vice president impractical (the U.S. ambassador and U.S. Attorney General Eric Holder represented the United States). In any case: When you’re Obama the one thing you can count on, day to day, is your doing something wrong, heinously wrong, either by commission or omission. The critics would also have been outraged if Obama had gone to Paris and made it all about him.

Condemnation  is the only currency today in political discourse. Whatever you’re doing, it’s wrong. That’s true of all American presidents and indeed all political leaders. Note, for example, the sharp criticism of French President Francois Hollande for excluding the far-right National Front party and its leader Marine Le Pen from the “unity” rally in Paris.

You can’t go into politics with a thin skin. This White House too often has started the day worrying about what’s trending on Twitter, and the day’s agenda too often is driven by message control. (My views on this are are shaped by my reporting on the Gulf of Mexico oil spill and Ebola.)

Another requirement for being a good president is the ability to enjoy the job. A good question for those who follow this president closely might be: Is his heart really in it? Day to day, does he enjoy the presidency? If so, why does he often seem like a guy who’s about to request a six-month leave of absence so that he can write a book?

The best presidents typically relished the position of chief executive. In the latest Doris Kearns Goodwin opus, “The Bully Pulpit,” the historian writes that Teddy Roosevelt rued the day in 1904 that he vowed not to seek reelection in 1908, because he loved the job so much. He said he’d cut off his right hand if he could take back that vow. (T.R. became president when William McKinley died of an assassin’s bullet in the summer of 1901, and left office in 1909 having served 7½ years, having been elected on his own only once; there was no constitutional term limit then, only the unwritten rule, established by George Washington, that two terms were enough). T.R. was succeeded in the White House by his friend William Howard Taft, who realized soon enough that he had the wrong temperament for the job and would have done better as chief justice, the job he’d long coveted.

The mystery is why anyone with any sanity would want to be president, particularly in this fractious age when entire networks are devoted to one’s demonization and oaths of ideological purity ensure that any partnership with the legislative branch will be impossible. Obama has discovered the joys of executive orders; look at his Cuba opening, which requires no congressional action for the moment. But even there, the presidency has limits. His political appointees occupy corner offices in buildings filled with civil servants who wield their own subtle authority. The bureaucracy moves at an oil-tanker pace. A president can issue an edict and realize that nothing has actually happened. Because there are procedures, rules, regulations — and everything takes time.

Why, exactly, does Mitt Romney want to be president, as he said Friday to a group of supporters? Why does Jeb Bush, someone who has always been lined up for a White House run but never quite seemed to need the job to feel wholly content with life? And why, after all the ugliness she saw up close during her White House years, does Hillary Clinton want to go back there?

Calling Richard Ben Cramer! Richard unfortunately is no longer with us, but his masterpiece “What It Takes” remains the best guide to the psychology of presidential aspirants. Still, it’s about the race in 1988, which is starting to feel a little bit dated. So: What will it take in 2016?