Those who tweet are sweet on Mr. Obama. Among self-identified users of Twitter, the social-media network in which users are limited to short messages, Mr. Obama’s approval rating stands at 69%, according to a new Wall Street Journal/NBC News poll. That is 23 percentage points higher than for the nation at large.

The Twitterverse is still a small world. Only 9% of adults said they used the service in the past two to three weeks, compared with 55% who said they used Facebook, the survey found.

Where Twitter leans left, Facebook reflects the electorate at large, due to its huge number of users. Among Facebook users, the president’s job-approval rating is 47%, statistically no different from the 46% for voters overall.