Gillion’s research examines whether a protest can make a real change – and the short answer is that it does. Looking at the effect of civil rights protests from the 1960’s–1990’s on Congress, he found that protest had a small but detectable effect on legislators. And he identified factors that increased the salience of a protest to politicians, including:  

• Whether the protest lasts longer than a day
• If there are more than 100 people involved 
• If political organizations were attached to the protest 
• If police were present 
• If there were arrests, injuries, or reports of property damage
• Whether a death occurred

“On average, every time a politician becomes informed of 10 protest events happening in their district, they become 1 percent more likely to support a bill that favors a protester’s position.”