I've seen a couple of law review articles discussing the conflict between free speech rights and this electioneering bubble for individual voters.

NPR: Can Your Clothes Keep You From Voting On Election Day?

Then-Chairman Greenspan's "irrational exuberance" speech was in December 1996, with the bulk of the dot-com bubble to follow, but the Fed didn't even hike reserve requirements to send a warning shot across Wall Street's bow.

FORBES: Magazine Article