Political leaders and law enforcement officials in Arizona are on high alert ahead of President Trump's campaign rally Tuesday night in Phoenix.

The big question is whether there will be more supporters of Trump inside the Phoenix Convention Center, which holds 29,000, or protestors outside.

Trump's response to the violence at a white supremacist rally in Charlottesville, Va., has become the biggest controversy to date of his presidency

The Phoenix rally, as a result, has become an opportunity for Trump's opponents to show their force.

Some GOP leaders, such as Gov. Doug Ducey, are steering clear of the rally entirely.

Trump is moving ahead with the event despite a plea from Phoenix Mayor Greg Stanton, a Democrat, that he stay away. 

Stanton said in a statement that he is "disappointed" that Trump would hold a campaign rally while the nation "is still healing from the tragic events in Charlottesville."

Phoenix Police Chief Jeri Williams said in a statement that her force will have "maximum staffing during the visit."

The department is "working 24/7 with our partners to ensure all of our resources are in place," Williams said.

Stanton said the city is committed to keeping everyone inside and outside the arena safe.