Could anything stop Harris from being the nominee?

When Joe Biden announced that he was abandoning his campaign for a second presidential term, he endorsed vicepresident Kamala Harris to replace him as the Democratic nominee.

- MARY DEJEVSKY

While this smoothes her path to the nomination, it does not absolutely guarantee that she will secure it.

Why can’t Biden decide who should replace him?

It would be a lot simpler if he could. But even the official nominee, as Biden was, cannot just designate a replacement if stepping down, for whatever reason.

Winning a party’s presidential nomination is the result of half a year of primaries and caucuses at state level that are part and parcel of US democracy. The process gives state-level legitimacy to the nominee eventually chosen. This year, the process was not as visible or protracted as it often is, because Donald Trump was the outright favourite for the Republican nomination and Biden, as the incumbent president, faced almost no opposition from his party so nominations were decided early.

In the event a nominee needs to be replaced, there is no time for the whole process to be repeated. But the principle that states decide on the nomination for the federal office of president is not something to be jettisoned lightly.