Erica Chenoweth, co-author of Why Civil Resistance Works: The Strategic Logic of Nonviolent Conflict says that it might take only 3.5% of the population of the United States to be involved in nonviolent resistance to stop the brutal regime of Donald Trump and Mike Pence. She points to the successes of political movements of the past.
"In the US on Tuesday, dozens of lawmakers have said they will boycott confirmation votes for Trump nominees. Numerous police departments countrywide have announced that they will not comply with unethical federal policies (particularly regarding deportations). And the federal government employs more than 3 million civil servants – people on whose continued support the US government relies to implement its policies. Many such civil servants have already begun important conversations about how to dissent from within the administration. They, too, provide an important check on power."
https://www.theguardian.com/commentisfree/2017/feb/01/worried-american-democracy-study-activist-techniques