Michelle Obama causes spike in social media comments

First Lady Michelle Obama on Tuesday caused the biggest spike in social media comments of any convention speaker in either party so far -- more than 30,000 per minute at her peak, according to analysis by Bluefin Labs in Cambridge.

Obama generated 30,510 comments per minute on Twitter and Facebook during her address at the Democratic National Convention in Charlotte, eclipsing Mitt Romney’s mark of 17,458 at last week’s Republican convention in Tampa.

Overall, the first night of the Democratic convention drove 1.3 million comments between 10 p.m. and 11:30 p.m., when the major television networks carried live coverage.

Opening night of the Republican convention generated 503,000 comments.

Fifty-six percent of those who commented on the Democratic convention were women, compared to 45 percent of those who weighed in on the GOP.

The total of 1.3 million comments on Tuesday made the first night of the Democratic convention the most talked-about television event of the election season on social media. The final night of the Republican convention, when Romney spoke, prompted 951,000 comments, and President Obama’s State of the Union address in January drew 881,000.