Our friends at the New York Sun and the Wall Street Journal have both published editorials (Sun, WSJ) urging President Trump to resign. I share the view that Trump's behavior in refusing to accept his election loss and in encouraging a mob that disrupted Congress has been seriously egregious to the point where it raises doubts about his fitness to hold the office, even for another couple of weeks. But it is worth considering, too, that there would be a downside to resigning.
Every presidency has its low points. George W. Bush had the period when the Iraq War seemed to be a quagmire. Reagan had the Iran-Contra affair. Clinton had the Monica Lewinsky affair and the impeachment that followed. Carter had the failed mission to rescue the American hostages in Iran. Johnson had the war in Vietnam. Nixon had Watergate. By the standards of presidential low points, Trump's last few weeks and last few days certainly do rate. But it is a slippery slope. When a president resigns at a low point, a risk is that it will weaken the institution of the presidency itself, to the point where the press and Congress are emboldened to hound any president out of office for whatever the latest outrage is.
Presidents are human. They are flawed. That is not to excuse President Trump's errors in judgment or character, which are significant. There is a kind of virtue in falling on one's sword, but there is also a kind of virtue in acknowledging one's mistakes and trying to do better. Trump seems to have a problem admitting he is wrong, which is a character flaw related probably to why he can't admit he lost the election. But if part of the point is to offer a moral example of taking responsibility for one's own actions, there's a case for Trump sticking it out and trying to do better, rather than for abandoning the post to which the voters elected him.
It'd be better for the country if President Trump and Melania were to meet graciously with President-Elect Biden and Dr. Jill Biden, give them the best possible advice, and attend the inauguration just as Hillary Clinton attended Trump's inauguration even though she believed her victory had been stolen by a Russian intervention. Because sometime in the next four years President Biden will appear senile or weak or clumsy or sexist or racist or incompetent or elderly or just failed, and there will be calls for him to step aside and let Kamala Harris take over. The best gift, the most logically consistent gift, that Trump can give the voters of America and the concept of democracy itself in the remaining days of his presidency is the assurance that the office will be held by the person the voters elected.