To wit, "we as a body have the power on any given day to change the rules with a simple majority."
The key phrase here is "on any given day." When we've reported on Reid's comments in the recent past, readers have expressed confusion about this exact point. Reforming the filibuster with a simple majority, they've come to believe, requires taking action on the first legislative day of a new Congress.
This stems, I think, from the strategy Democratic filibuster reformers have adopted for over two years now, and on the way that strategy has been portrayed in the press. But it's mistaken.
Filibuster reformers organized around taking action on the first legislative day because there's little precedent for attempting to reform the filibuster in the middle of a session, and because there's perceived political value in not changing the rules mid-play.
But there is nothing in principle preventing Senate Democrats from invoking the same process today, tomorrow, or any day, as long as they remain in power. Remember, Republicans threatened the "nuclear option" over judicial nominations eight years ago when they were in the majority in the middle of session. And though that threat, like most other filibuster reform threats, was ultimately defused, Democrats took it seriously because it was actionable. A few prominent liberals even counseled Democrats to let Republicans have their way, on the principle that a Senate majority should be able to carry out the Senate's duties where not explicitly excepted in the Constitution, and the anticipation that there might be a Democratic president in the future.
So Reid really could do this. His threat may be idle -- and that's a mystery for Republicans and filibuster reformers alike to solve -- but it's not illegitimate.