Is there an "elephant" stampede in the making?

As many in the GOP Congress announce that they are NOT running for re-election, including about 5 in the Senate (and one Senator who deserved a SHAME award in Idaho, but instead got a surprise fame award) and 12 in the House so far, one has to ask the inevitable question of whether this is a trend and whether it is a trend that is indicative of an "elephant" -- as in GOP -- stampede?