Trump campaign manager Paul Manafort indicated Sunday that he sees the convention as an unalloyed opportunity for Trump on that score. The convention’s first night, he said, will be focused on how to “make America safe again.”

Whether the convention accomplishes that goal rests on two things that are uncontrollable by Manafort or event organizers: an outbreak of violence here or elsewhere, and Donald Trump.

Under some circumstances, Trump could benefit from the environment of violence this year. Candidates who portray themselves as the “law and order” alternative have succeeded before; unrest has, if anything, amplified the message of candidates like Richard Nixon, who benefited from protests at his 1968 convention.

But Trump himself has been accused this year of fomenting violence with remarks aimed at protesters inside his events, so he could be seen in some quarters as lacking real concern for outbreaks. That possibility is magnified by his reactions to charged events, which have sometimes been layered with insouciance rather than sobriety.