Presidents' audiences have been shrinking over time. Prior research suggests that the rise of cable television is to blame. We investigate whether this shrinkage is occurring disproportionately among those the president most needs to persuade—disapprovers of his performance. Analyzing both A. C. Nielsen's audience ratings and self-reports of speech watching from 32 postspeech surveys, we find that as the share of households subscribing to cable has grown, the statistical relationship between the president's approval rating and the percentage watching his televised speeches has strengthened commensurately for each group of party identifiers. Consequently, as presidential approval ratings have polarized during the past two decades, so too has the partisan composition of presidents' audiences, a phenomenon unknown during the broadcast era. Modern presidents thus find themselves increasingly preaching to their party choir and losing the capacity to influence public opinion more broadly.