The Donald Trump campaign rolls into Lowell today — and will be met not just by throngs of supporters. But protesters say they have been drilling on how to handle tensions and potential scuffles, and add they expect more anti-Trump activists than the designated protest space can accommodate.

Jay Monaco of Community Advocates for Justice and Equality, which opposes the Republican presidential front-runner’s deportation plans for immigrants, said he expects 300 to 400 protesters outside the Paul E. Tsongas Center.

“This is looking like the biggest event of its kind in Lowell that anyone can remember,” Monaco said. “Everything that we’re emphasizing is really to minimize danger. Self-defense if absolutely necessary, but de-escalation whenever possible.”

Supporters and protesters have clashed at recent Trump events. In November, Trump supporters and activist Mercutio Southall got physical at an event in Alabama. Southall is pursuing charges.

Alexis Toliver of Black Lives Matter Cambridge, which also will protest tonight, said the group “only will be focused on saying the names of people who have been hurt by Trump,” and have “no intention to get near Trump.”

It’s the Trump campaign’s second rally in the area. The campaign has close ties to Lowell. Campaign manager Corey Lewandowski is a Lowell native and a University of Massachusetts Lowell graduate.

The event will be secured by Trump’s private team and Lowell police. The university said it has limited involvement in the event, which is under the control of its professional management company, Spectra Venue Management, which books the Tsongas Center for external events.

Monaco said his group wants to negotiate a larger protest area.

“It’s been clear to the police and to the city itself that with the attention that this is garnering, the little area that they were going to cordon off for us is probably not going to be sufficient,” Monaco said.