Obama, Amash battle on Twitter

President Obama deployed Twitter in his shutdown battle against House Republicans, and got some blowback from a prominent GOP conservative.

Obama, who has stepped up his attacks on House Speaker John Boehner, R-Ohio, tweeted to supporters: "Tea Party extremists caused this #BoehnerShutdown. Tell @SpeakerBoehner to end it now:"

An avalanche of responses included one from Rep. Justin Amash, R-Mich.

Said Amash to Obama: "Way to uphold the dignity of the office."