In 2005, Republicans’ and Democrats’ views of their own parties dovetailed with the perceptions of the electorate as a whole. Today, while voters as a whole agree with Republicans’ evaluation of their party as conservative, they disagree with Democrats, who on average see their party as moderate rather than liberal. So when Independents, who see themselves as modestly right of center, say that Democrats are too liberal, average Democrats can’t imagine what they’re talking about.

Compounding the problem, the American people are gradually polarizing. According to Gallup, twenty years ago, as Bill Clinton began his presidential campaign, self-described moderates formed the plurality of the electorate—43 percent; conservatives were 36 percent, liberals 17 percent. By the summer of 2011, the conservative share had risen to 41 percent and liberals to 21 percent, while moderates declined to 36 percent, surrendering their plurality status to conservatives. Because nearly all conservatives now vote for Republicans and liberals for Democrats, the share of the shrinking pool of moderates that Democrats need to build a majority is now larger than ever.

Another Gallup finding that should alert Democrats is the ongoing collapse of public confidence in government.