A Potential Weakness in Bernie Sanders' Coalition? The Politically Disengaged

Among Democratic primary voters who said they are “not at all interested” in politics or public affairs, 31 percent said Sanders was their first choice for president – more than any of the other 18 names surveyed. The poll of more than 15,383 Democratic primary voters was conducted Feb. 11-17, before Sanders entered the race, and has a margin of error of 1 percentage point.

Sanders’ lead among those voters could give him a decisive edge in the primary if a potentially untapped base of voters show up to the polls. But it could also serve as a warning sign for comparatively soft support, as uninterested voters tend to be less likely to vote.

“If Sanders doesn’t mobilize his supporters to vote, then their support doesn’t really matter in the discussion about winning the Democratic nomination. You don’t get bonus points for attracting non-voters. Primaries are generally decided by the most interested and engaged people,” Nathan Gonzales, a nonpartisan elections analyst who runs Inside Elections, said in an email. ”But, with President Trump in office, the stakes are high for Democrats and the nominating process could attract more interest, including more casual voters.”

Kyle Kondik, managing editor of Sabato’s Crystal Ball at the University of Virginia Center for Politics, said Sanders may be benefiting from high awareness among the public after mounting a more competitive-than-expected challenge to Hillary Clinton for the party’s nomination in 2016.

Sanders’ insurgent campaign attacked Clinton from the left, pushing for a single-payer health care system that has been embraced by some prominent Democrats and 2020 contenders. His success in shifting the debate leftward was highlighted Tuesday by Republicans: A spokeswoman for Trump’s re-election campaign said in a statement that Sanders “already won the debate in the Democrat primary.”