Let's start with Club for Growth. It's out to destroy any member of Congress who votes his/her conscience. Take one Illinois House member, conservative to the core but unwilling to let government close down. He's under constant pressure from extremist groups with big, big money.
... Lawmakers considered suspiciously squishy by the Club for Growth were designated as RINO’s (Republicans in name only), and the club has vowed to find primary opponents and support them with cash — a formidable threat considering that it spent $18 million backing conservative candidates in the 2012 cycle. Americans for Prosperity, a Koch brothers group that has already spent millions on ads fighting health reform, is beginning a new campaign to delay the law’s effects.
These groups, all financed with secret and unlimited money, feed on chaos and would like nothing better than to claim credit for pushing Washington into another crisis. Winning an ideological victory is far more important to them than the severe economic effects of a shutdown or, worse, a default, which could shatter the credit markets. ...NYTeditorial
It's not as though there's anything new here. What's new is the amount of money and the extent of latitude allowed to these groups by conservative courts. Fascism isn't yet standing in the sunlight and targeting democracy. Not quite. It's just over there, visible but still in the shadows.