Unless/until Kamala Harris is actually nominated, her endorsement by President Biden may be a test balloon for how she might fare in the general election against President Trump. The first level of analysis will be whether she might actually win the election, but the second level of analysis will be her effect on down-ballot elections. It is one thing to concede the White House to Trump, but quite another to provide him with substantial majorities in both the House and Senate. If the latter appears likely during the next three weeks, we may see Kamala withdraw her candidacy in favor of another nominee.