The bully pulpit has a new kind of altar call: “Tweet them. We’ve got a hashtag. Here’s the hashtag for you to tweet them: #dontdoublemyrate.”…

Within moments after Obama finished his remarks, Twitter users had written more than 20,000 posts containing “#dontdoublemyrate” — enough for Twitter to declare it a top 10 worldwide “trending topic.”

The six-year-old microblogging site came into its own this presidential cycle, but the past few weeks have demonstrated how clearly it has become the tool of choice for getting something into the political bloodstream, from manufacturing a battle over who can be called a working mom to building a movement around a piece of legislation.