The Tories are shit scared of the far right as the natural inclination of their party leans that way, so they see it as a threat to their ability to stay in power by bleeding votes and support to those fringe, Farage/Tice parties.
They shit themselves over losing two MPs to UKIP that they fecked the country via the Brexit referendum, so she is just trying to invoke the same stuff.
It's not about the amount of hooligans she can manifest, it's that she can do that at all, it's showing public support and more crucially, the internal racists in the Tory party get to see her acting like a tinpot Marie Le Pen.