Those raucous crowds at town meetings held by GOP congressmen are in large part the work of a new left-of-center group known as "Indivisible," Newsmax has learned.

Its goal is to imitate the success of the "Tea Party" against Democrats and the Obama administration eight years ago.

Newsmax has obtained a 26-page manual, dated January 27, 2017, that spells out a course of action for enemies of President Donald Trump and what it calls his "attempt to use his congressional majority to reshape America in his own racist, authoritarian, and corrupt image."

Entitled "Indivisible: A Practical Guide for Resisting the Trump Agenda," the manual spells out how to influence members of Congress who, in its words, "care more about getting re-elected than they care about any specific issue."

As to just who is behind "Indivisible" and the movement it hopes to create, the authors identify themselves simply as "former progressive congressional staffers who saw the Tea Party beat back President Obama's congressional agenda."

Among those listed with their Twitter handles as part of the "@IndivisibleTeam" are @ezralevin (Ezra Levin, formerly with Americorps and the U.S. House, now "executive director" of @InvisibleTeam) and @angelrafpadilla (identified on Twitter as a "health and immigrant rights advocate").

By adopting its tactics in dealing with U.S. representatives and senators, "Indivisible" assures its adherents it will achieve such goals as to "Stall the Trump Agenda by forcing them from their priorities" and to "Reaffirm the illegitimacy of the Trump Agenda."

"A day that they spend worrying about you," the manual boasts, "is a day that they're not ending Medicare, privatizing public schools, or preparing a Muslim registry."

"Indivisible" then goes on to spell out the mechanics of a congressional office and staff and encourages supporters to "[F]ind out where your MoC's [Members of Congress] stand on the issues of the day" which it identifies as "appointments of white supremacists, tax cuts for the rich, etc."

But a good portion of the manual spells out tactics for town hall meetings of Members of Congress — which are now clearly in operation, as one can see from news reports that have led to Republican lawmakers such as Iowa Sen. Joni Ernst and California Rep. Tom McClintock to cut short their meeting.

"Don't give up the mic[rophone] until you're satisfied with the answer," town hall participants are advised, adding that staffers cannot take back a mic immediately "if you keep a firm hold on the mic. No staffer in their right mind wants to look like they're physically intimidating a constituent, so they will back off."

Should staffers object, the manual advises them to say "politely but loudly: 'I'm not finished. The MofC is dodging my question. Why are you trying to stop me from following up?'"

In tactics that are strikingly reminiscent of the liberal demonstrators against the House Committee on Un-American Activities in 1960 or the "New Left" protests against the Vietnam War a few years later, "Indivisible" activists are advised to interrupt and be heard at other public events House Members and senators participate in. Some examples listed are groundbreaking ceremonies and parades.

"Agree beforehand with your group on a simple message focused on a current or upcoming issue," the manual advises, "Coordinate with each other to chant this message during any public remarks that your Member of Congress. This can be difficult and a bit uncomfortable.

But it sends such a powerful message to your MofC that they won't be able to get press for other events until they address your concerns [emphasis added]."

"Indivisible" also encourages what it calls "non-citizens" to participate.

Recalling how the emerging Tea Party groups "could be fewer than ten people but they were highly localized," the manual calls for similar grass-roots recruitment on the left and even suggests tea party-like names for local chapters such as "Springfield Indivisible Against Hate."

For now, it is clear that its tactics in the disruption of town meetings and making news by doing so are succeeding.

Whether "Indivisible" will evolve into a true grass-roots movement that packs a political punch akin to that of the Tea Party and whether it attracts big money on the left from George Soros and others remains to be seen.