CHARLESTON, S.C. (CN) – Katie Preston couldn’t believe her eyes. Eleven months ago she’d been shocked into political activism by the election of Donald Trump as president. Now, on a Facebook timeline, she was being told that Steve Bannon, executive chairman of Breitbart News and chief architect of Trump’s victory was coming to her hometown for a Friday night speech at the Citadel.

“I was taken aback,” Preston says.

“I mean, he’s just such a nasty guy. Horrible about women. Horrible about Jewish people. Minorities. And he’s going to be speaking just down the street from the Mother Emanuel AME Church, where nine people were murdered by a white supremacist,” she says.

“I mean, c’mon. Don’t bring him here. It’s a slap in people’s faces,” she adds.

Preston is the chairperson of Indivisible Charleston, a grassroots group that seems to confirm an adage attributed to Hunter S. Thompson that all political movements give rise to an anti-movement of equal and opposite force.

“We’re part of the resistance,” Preston says with a laugh as she pulls up the group’s website to quote its mission statement word-for-word.

“Indivisible Charleston seeks to mobilize citizens in the Tri-County area to participate in the democratic process, to promote systemic equity and justice, and facilitate civil discourse in the political arena,” she says.

“So this — this group, your role in it — is a direct reaction to the Trump election?” a visitor asks.

“You bet ya,” she says.

Bannon was invited to Charleston by the student-led Citadel Republican Society to speak at its annual “Patriot’s Dinner.” He’ll be making remarks at the college’s Holliday Alumni Center. It wasn’t until after he accepted the invitation that the school itself, one of the South’s most historic colleges, got wind of his imminent arrival.

Citadel president Lt. Gen. John Rosa has since expressed regret over not getting in front of the invitation earlier, but said in a statement that it would be wrong to intervene and try to keep Bannon away.

He said college does not endorse political figures or partisan points of view and is committed to academic freedom and freedom of expression.

Brady Quirk-Garvan, chairman of the Charleston County Democratic Party, said he was disappointed the Republican Society invited Steve Bannon to come speak at the Citadel.

“Bannon is an unabashed white nationalist and racist, and he is not welcome in Charleston. The Republican Society should be ashamed for bringing this racist bigot to the Holy City,” Quirk-Garvan said.

But Charleston GOP Party Chairman Larry Kobrovsky said condemning Bannon before he speaks isn’t fair.

“There is so much noise about who or what Bannon is,” he said. “Let the guy speak and let people draw their own conclusions. To suggest that the guy couldn’t come and speak is repulsive. We should hear from everybody, but I reject any kind of racial nationalism — white, black or Hispanic.”

Preston got on the phone with local Democrats and Pastor Thomas Dixon, co-founder of People United to Take Back Our Community, an organization originally founded to combat neighborhood crime, but has widened its mandate to address a wide range of local issues.

Pastor Dixon secured a permit from the City of Charleston for Friday’s anti-Bannon rally, and says organizers have done everything they can to ensure it is a peaceful event and “doesn’t turn into some Charlottesville mess,” a reference to the white supremacist rally in Virginia last summer that left one counter-protester dead and several injured.

The rally will feature a lineup of speakers offering presentations on the rights of women, Muslims, Hispanics, diversity, Jews, and the LGBTQ community.

There will also be a speech focusing explicitly on Bannon’s visit in the context of the Mother Emanuel church murders.

“Bannon loves to stir controversy,” Preston says. “That’s not our aim. We don’t intend to stand outside the dinner and yell and carry on. Our goal is the present alternatives to the ideas he espouses.”

The Charleston Police Department isn’t taking any chances. It is closing several local streets surrounding the Citadel beginning at 3:30 p.m. and intends to keep them closed until about 10 p.m.

A spokesman for the department says the move is an effort to accommodate everyone and “ensure the safety of everyone involved.”

The indivisible movement actually traces its roots to Washington, DC where, dismayed by the outcome of the 2016, a group of shaken former congressional staffers gathered to take stock of what to do next. It was just days after the election, but already, they agreed, momentum was building to fight the Trump agenda tooth and nail.

The problem was that energy and commitment was abundant, but direction and consensus less so. What was needed was a model. The former Capitol Hill staffers set out to write one.

On Wednesday, Dec. 14, 2016, a Google document entitled “Indivisible: A Practical Guide for Resisting the Trump Agenda” began making the rounds on Twitter accompanied by the message “Please share w/ your friends to help fight Trump’s racism, authoritarianism, & corruption on their home turf.”

The premise of the guide was simple: Signing petitions and calling your local representative would accomplish little in the new political climate. What was needed was for those who call themselves liberals or progressives to learn from the lessons of Tea Party activists.

That meant engaging in locally focused, defensive advocacy to protect the left’s values; using elected officials’ desire to be reelected to influence them; and building constituent power locally, focusing laser-like attention on your own congressmen or women and making your voice heard at their town halls, other public events, district office visits, and mass calls.

“The guide was essentially the Tea Party playbook and it just took off … Local Indivisible groups started popping up everywhere,” Preston says. “And now it’s this huge thing.”

Preston first heard about the group while watching “The Rachel Maddow Show” on MSNBC and was excited to learn that someone had already started a Facebook page for a group in Charleston. However, the group’s first small rally, held last winter, was a bit of a flop. That inspired Preston and a handful of other members to commit to getting together and creating more of a structure for its activities.

In short order, she became the chair and the group also named legislative and outreach coordinators, and a leadership team. It also filed the paperwork to become a nonprofit, a 501C4, so that it could support political candidates.

Somewhat surprisingly, Indivisible Charleston’s core group of members are what Preston describes as “older women.”

“Women between 40 and 70 … and a few men in their 50s and 60s,” she says. “We have some young people, but not as many as you would think.”

“A lot of millenials are very far left,” Preston says, seeking to explain. “We are more progressive … but not ‘out there,’ so to speak. In Charleston specifically a lot of the real young people are really anti-government in general. They’re angry at everything right now. We, on the other hand, are trying to fix government.”

Even without Steve Bannon’s appearance to rile them, the members of Indivisible Charleston have been making their voices heard. They hold rallies every Tuesday, their venues alternating between the local offices of Sens. Lindsey Graham and Tim Scott, and Rep. Mark Sanford.

“Sometimes there’s 15 people; other times there are 30 or more, depending on what the hot topic is,” Preston says. “We hold a rally outside their offices, then we go inside and talk to staffers about whatever the latest issue is that we are concerned about.”

Sweeping Democratic victories in Tuesday’s election, including Democrats winning governorships in Virginia and New Jersey, has Invisible Charleston members “ecstatic” as they prepare for Friday night’s rally outside Bannon’s appearance at the Citadel.

“Everybody’s got kind of a good vibe right now,” she says.

Preston says while Friday’s event has galvanized those who opposed President Trump’s policies and Bannon’s ideas, it’s just one event in one are sure to be many on the march toward the congressional mid-term elections.

“I don’t think Friday’s rally is going to change what we do or what he does,” she says. “I don’t think you can get us any more excited about or committed to what we’re doing. But I think it’s important to stand up and say, ‘We don’t appreciation you being here.'”