A branch of the Ku Klux Klan forced by the US government shutdown to cancel a rally outside the civil war cemetery in Gettysburg on Saturday now pledges instead to gather in the historic town itself.

Wearing their infamous pointed white hoods and robes, the group is set to embark on a bizarre charm offensive by denouncing the traditional Klan tenet of white supremacy – talking instead of supporting soup kitchens and orphanages.

The Confederate White Knights of the Ku Klux Klan (KKK) have been barred from holding a demonstration at the legendary civil war battlefield in the southern Pennsylvania town because the site is located within a national park. All US national parks have been closed since Tuesday.

But were it not for the government shutdown that, the White Knights would be able to rally at the battlefield site with the permission of park rangers and the federal authorities by virtue of free speech rights.

Those rights, under the first amendment to the US constitution, now mean, however, that the group can rally in full KKK regalia in the small town of Gettysburg itself, provided they meet on public land.

The tiny Gettysburg police department has tried in vain to speak to Richard Preston, 48, the imperial wizard of the Confederate White Knights, about his plans for Saturday.

"If this goes ahead and they get to a point where they are affecting the quality of life here, that would be disorderly conduct. But just because you may find them offensive that does not make it illegal," said police chief Joe Dougherty.

Preston told the Guardian that his group were currently scouting for the most appropriate eligible site close to downtown, where they plan to espouse a fresh message.

"It's not about racism any more. That was in the 60s and 70s," he said.

Preston said he broke away from a larger KKK branch to form his own in a bid to dissociate himself from white supremacy and neo-nazism.

"We are not claiming to be supreme. We are not supremacists; we are white separatists," he said, arguing that there should be tolerance though not free association between people of different racial backgrounds – as long as they are legal citizens and employed.

His group's main grievances are directed at undocumented migrants and a desire to oust President Obama from office – on the basis of persistent extremist arguments that he is not a genuine American citizen.

A leading civil rights campaign body has warned that the rapid growth of extreme rightwing 'patriot' groups indicates increased risk of domestic terrorism on a scale not seen since the Oklahoma City bombing in 1995.

Gettysburg has fewer than 8,000 residents but attracts more than 2million tourists annually to the site that 150 years ago hosted the civil war'spivotal and bloodiest battle – and President Lincoln's historic speech.

Preston will not reveal the size of his branch of the KKK. He said hehas support from groups in Kentucky, Florida and Georgia.

He longs to organise a KKK march down Pennsylvania Avenue to the WhiteHouse, just like one he claims attracted 100,000 klansmen in the 1920s.

"We are growing constantly," he said.

He said the klan became too violent during the civil rights era but had a social conscience during the 1920s.

"We want to bring the good name back," he said.

Preston claimed the klan organised soup kitchens in the 20s and raised money to support orphanages – deeds he wants them to revive.

To be a member of the Confederate White Knights of the KKK, however, the group specifies that alongside citizenship you must be white, straight and a Christian – without any criminal convictions for child molestation.

Preston admitted the group indulges in cross-burning.

In a report earlier this year the Southern Poverty Law Center, a civil rights pressure group, found that there are 1,360 so-called patriot groups in the US – defined as rightwing, conspiracy-minded, anti-government activist groups.

That number is up by 813% since 2008 and has reached an all-time high. In addition the SPLC records just over 1,000 specific hate groups in the US, including the Ku Klux Klan, which are also on the rise.

"We are living at a very worrying moment. The radical right is growing rapidly and it seems entirely possible that we will see another major domestic terrorist attack along the lines of the Oklahoma City bombing," said Mark Potok, a senior fellow at the SPLC, referring to the bombing of a government building there by white supremacist Timothy McVeigh in 1995 that killed 168.

Potok added that Preston's claims that his branch of the klan is not racist are "absurd".

guardian.co.uk © Guardian News and Media 2013

["Ku Klux Klan" by Arete13 via Flickr, Creative Commons licensed]