The election of Donald Trump has brought new people into politics and re-ignited activists. As people on the left aim to resist what they view as Trump’s dangerous and harmful policies, and people on the right try to sustain political engagement after the election, both sides are debating about the effectiveness of various political strategies. For example, Indivisible, a guide compiled by Congressional staffers on tactics for opposing President Trump, spread quickly across the internet as people grappled with how to effectively influence policy-making.

Contacting legislators is one of the most common forms of political engagement in the United States. Hearing from constituents, particularly in face-to-face meetings and phone calls, can influence politicians’ action on an issue. The greatest impact, however, is when the contact is outside of routine communications and part of a collective campaign. Social scientists have found that politicians are more likely to react to new information that indicates a change in the political landscape and ties their stance  to their electability. An organized effort can demonstrate that a group has powerful resources, such as volunteers and donations, which in turn can affect politicians’ ability to get re-elected.

• Daniel E. Bergan and Richard T. Cole. 2015. “Call Your Legislator: A Field Experimental Study of the Impact of a Constituency Mobilization Campaign on Legislative Voting.” Political Behavior 37(1): 27–42.
• Sidney Verba. 1995. Voice and Equality: Civic Voluntarism in American Politics. Harvard University Press.
• Paul Burstein and April Linton. 2002. “The Impact of Political Parties, Interest Groups, and Social Movement Organizations on Public Policy: Some Recent Evidence and Theoretical Concerns.” Social Forces 81(2): 380–408.

Legislators are not always just responding to public opinion either. They are also influenced by lobbyists, political donations, personal political views, and party platforms. Nevertheless, popular opinion may play a larger role in shaping elected officials’ positions when it signals a dramatic shift and the public feels strongly on one side of an issue. Thus, political organizations and concerned citizens can influence policy by raising and changing public awareness, and then explaining these popular sentiments to politicians who learn about their constituents attitudes.

• Susanne Lohmann. 1993. “A Signaling Model of Informative and Manipulative Political Action.” The American Political Science Review 87(2): 319–333.
• Daniel M. Butler and David W. Nickerson. 2011. “Can Learning Constituency Opinion Affect How Legislators Vote? Results from a Field Experiment.” Quarterly Journal of Political Science 6(1): 55–83.

The effectiveness of contacting politicians also depends partially on the party and race of the official and the constituent. People are more likely to contact a politician from their own political party, so contacting leaders outside of one’s own party disrupts political norms — which is sometimes effective and sometimes discounted. The response of elected officials to the public is also shaped by racism. For example, a real-world experiment found that white legislators discriminate against emails and calls from black constituents.

• David E. Broockman and Timothy J. Ryan. 2016. “Preaching to the Choir: Americans Prefer Communicating to Copartisan Elected Officials.” American Journal of Political Science 60(4): 1093–1107.
• Daniel M. Butler and David E. Broockman. 2011. “Do Politicians Racially Discriminate Against Constituents? A Field Experiment on State Legislators.” American Journal of Political Science 55(3):463–77.

Although calling and writing legislators has a role in democracy, historical research shows that sustained mass social movements are what drive major changes in society and politics. Large popular movements that use tactics like protests, boycotts and strikes can disrupt the status quo and garner public attention. For example, during the U.S. Civil Rights Movement, sit-in protests increased the likelihood of desegregation in a city. The effectiveness of mass mobilization depends on the political and social context, but can transform political possibilities and lead to policy change.  

• Sidney G. Tarrow. 1994. Power in Movement: Social Movements, Collective Action, and Politics. Cambridge University Press.
• Doug McAdam, Sidney G. Tarrow, and Charles Tilly, eds. 2001. Dynamics of Contention. Cambridge University Press.
• Frances Fox Piven and Richard A. Cloward. 1979. Poor People’s Movements: Why They Succeed, How They Fail. Vintage books.
• Michael Bigg and Kenneth T. Andrews. 2015. “Protest Campaigns and Movement Success: Desegregating the U.S. South in the Early 1960s.” American Sociological Review 80(2): 416.