You may have heard the theory that Silicon Valley has been instrumental in the rise of Donald J. Trump.

The idea goes like this: Unlike many of his political rivals, Mr. Trump seems to understand that social media has become the nervous system of the American news business. On Twitter, where he regularly regales his millions of followers with 140-character bursts of id, Mr. Trump’s posts are mainlined and amplified by the rest of the media; with one or two tweets, he can dominate cable TV, the web, newspapers and talk radio for an entire day. The pattern was on display again this week, when Mr. Trump blasted The New York Times over a critical story about his treatment of women.

This theory is not exactly bunk. It’s true that Mr. Trump’s Twitter feed, with its staccato cadences and unending exclamation marks, can be irresistible even to his critics. He is among a handful of politicians who use Twitter as real people do — casually, bitingly and free of the jargon that clogs up most other pols’ tweets. Mr. Trump has also cultivated a Twitter fan base that can be domineering in its attempts to harangue and silence critics, another force multiplier in the day-to-day war for media dominance.

But don’t bet that Mr. Trump’s mastery over social media will help him in November. He has used Twitter as a tool to foment culturewide rage — it’s his big, inescapable bullhorn. Yet winning a presidential campaign involves more than simply whipping up unfocused outrage. It also requires more discrete, personalized messaging targeted to specific sets of voters and potential volunteers, a goal for which Twitter is spectacularly ill suited.