President Donald Trump's savvy use of Twitter has spawned a grassroots nation of followers who pump out tens of thousands of tweets every day in support of #MAGA, Politico reported.

The genesis in 2015 of private rooms on Twitter provided a home for ardent supporters of Trump who are committed to amplifying the president's message through tweeting and, especially, retweeting.

Retweeting is "the cardinal rule," Politico reported.

The invite-only rooms hold up to 50 people, and many people are in multiple rooms, sometimes 20 or more.

"The whole idea is to share tweets and retweet people in the group’s tweets," Brian Fraser, who manages one of the "Patriots United" rooms, told Politico.

Since last summer, Fraser's followers increased from 13,000 to nearly 170,000 today.

It's common for one person to tweet and retweet hundreds of times daily.

"This is clearly tapping into a group of people that are zealous, have a lot of time on their hands, and are tenacious as can be," Dr. Alan Rosenblatt, an expert in the history of online political campaigning, told Politico.