Sen. Arlen Specter's announcement that he would switch parties to pursue reelection as a Democrat drew surprise quickly from his Democratic Senate colleagues.

A one-word response characterized Democrats' response: "Wow."

Sen. Claire McCaskillClaire McCaskillWashington Post reporter compares DC rioters to Boston Tea Party Dem senator: Violent inauguration protesters ‘disgusting’ Five things to watch for in Mnuchin hearing MORE (D-Mo.) tweeted:
Specter to switch parties? Wow.


Sen. Bill NelsonBill NelsonPanel to vote on Trump’s Transportation nominee Tuesday Week ahead: FCC soon to be in Republican Pai's hands Meet Trump's secret weapon on infrastructure MORE (D-Fla.) shortly followed up:
Whoa, Arlen Specter is switching to Democratic Party after three decades in GOP


The surprise announcement was met with shock well beyond the walls of Congress, however. Tweets from bloggers, pundits, and journalists all expressed surprise at the announcement today.