Joe Biden is running. The former vice president will make his candidacy official with a video announcement next Wednesday, according to people familiar with the discussions who have been told about them by top aides. Seriously, he’s actually made a decision. It’s taken two years of back-and-forth, it’ll be his third (or, depending on how you count, seventh) try for the White House, and many people thought he wouldn’t do it, but the biggest factor reshaping the 2020 Democratic-primary field is locking into place. He wants this. He really wants this. He’s wanted this since he was first elected to...