I want to say unprecedented, but I’m sure someone somewhere will dig up something in the past where more incumbents were voted out in the primary by challengers from their own party. It happened in Kansas today…11 incumbents voted out.
As an unaffiliated voter, my biggest beef (and quite frankly the Democrats and Hillary are guilty as hell of this), is that the party in power decides that no, no one else is going to run in that primary. With a roughly 17% approval rating and a whopping 85% re-election rate, I really wish that all primaries would be open to challengers of their own party.
Technically you can say “they are” but the state parties look very unfavorably on challengers, and it can come with repercussions.
I applaud the Kansas Republicans for putting forth so many challengers…and winning. We need more of this in America, from both sides of the aisle.
I found an interesting paper that goes through a lot of incumbent challenges. It’s worth a read. You can find it here: http://www.cfinst.org/pdf/papers/Boatright_2014_Primaries_in_Context_9-30-14.pdf