McGregor's research focuses on political communication, journalism, public opinion, and gender. Overarching themes in McGregor's research include the role of social media and their data in political processes. McGregor's published work examines how three groups – political actors, the press, and the public – use social media in regards to politics, how that social media use impacts their behavior, and how the policies and actions of social media companies in turn impacts political communication on their sites. McGregor uses diverse methodologies like surveys, experiments, and large-scale computational and network analysis, as well as qualitative methods like in-depth interviews, to understand political events in socially networked digital spaces.
Notes that journalists have long wanted to see and report public opinion clearly. Shows that amid declining trust in polls and crises in polling methodology, journalists have been turning to social media, mostly Twitter, to understand public opinion.
Finds technology companies publicly resist being labeled as arbiters of political speech. Shows how they actively (and non-transparently) regulate political speech.
Brings together leading scholars to shed light on how big data can inform political communication research.
Indicates that the routinization of Twitter into news production affects news judgment. Finds journalists who said they spend a lot of time on Twitter and rely on it for their work ranked anonymous tweets as newsworthy or as more newsworthy than AP headlines.
Shows how Facebook, Google, and Twitter employees played an active role in shaping messaging and targeting in 2016 presidential campaigns, including embedding employees within the Trump campaign
Finds that people react positively to social media from politicians that highlight personal aspects of their life alongside policy. Finds this type of messaging can increase an individual's likelihood to vote for a particular candidate, but this impact is greater for male candidates than female candidates.