For as long as I can remember, the two parties have each tended to rely on a favorite theme when attacking each other: the Republicans accuse the Democrats of adhering to an extreme ideology, while the Democrats accuse the Republicans of supporting extreme policies. As Matt Grossmann and I explain in our forthcoming book, there are good strategic reasons for each side to adopt its favored strategy; most Americans lean to the political right in general terms but hold left-of-center views on specific issues, so politicians respond by attempting to shift the public debate of the campaign onto turf that favors their own partisan interest.
Four years ago, the party conventions followed this pattern closely. The Republicans spent an entire evening at their 2012 convention in Tampa portraying Barack Obama as a big-government collectivist who was instinctively hostile to the private sector and individual entrepreneurship. The best-received speech of the Democratic convention in Charlotte, Bill Clinton's "explainer-in-chief" address nominating Barack Obama for a second presidential term, methodically criticized Romney's positions on a number of specific policy questions as unacceptably hostile to the interests of ordinary Americans.
But the events of 2016 have prompted both sides to rewrite their playbooks a little. There was still a fair amount of traditional conservative rhetoric at the Republican convention last week—particularly visible in the speeches of Ted Cruz, Paul Ryan, and vice presidential nominee Mike Pence—but Donald Trump's acceptance address, like his campaign up to this point, relied on themes of American nationalism more than the limited-government principles ordinarily emphasized by Republican candidates, and his chief line of attack against the Democratic opposition was not that it was excessively liberal in a philosophical sense but that it was unacceptably permissive in the face of terrorism and lawlessness. Republican criticisms of Hillary Clinton, while numerous, primarily focused on the topics of the events in Benghazi and her private email server, and thus questioned her honesty, competence, and devotion to American interests more than her supposed leftism.
For Democrats, Trump's nomination presented its own novel challenge. As usual, the party's national convention this week promoted its own extensive set of policy positions, but Democrats' normal practice of characterizing Republican policies as extreme by comparison was frustrated by the fact that Trump, though he has expressed support for nearly all of the usual Republican domestic policy agenda, has not made limited government a defining theme of his campaign. Democrats who normally delight in presenting themselves as the defenders of popular entitlement programs and opponents of "giveaways" to corporations and the wealthy seem to have concluded that Trump's own personal attributes represent better attack fodder than his policy positions (such as they are). They repeatedly characterized Trump as inexperienced, ill-tempered, and divisive, with Barack Obama even referring to the Republican nominee as a "homegrown demagogue."
Most strikingly, the Democratic Party's essential nature as a coalition of social groups was on display to an unprecedented extent in Philadelphia. The Black Lives Matter cause and the Mothers of the Movement were given prominent platforms and expressions of support. Undocumented Latino immigrants spoke on Clinton's behalf, and a number of speakers, including the party's vice presidential nominee, punctuated their remarks with Spanish words and phrases. Other groups that received explicit representation from the convention stage included Asian Americans, Native Americans, feminists, gays and lesbians, transgender people, Muslims, union members, and people with disabilities. Clinton's status as the first female major-party presidential nominee and potential first female president was celebrated repeatedly during the convention proceedings—including via a video effect on Tuesday night in which a mosaic of (male) presidential portraits broke apart with the sound of shattering glass to reveal Clinton's face as she appeared live from a remote location to greet the delegates.
For much of the last few decades—especially the 1990s, when the current nominee's husband was the national leader of the party—Democrats tempered such tributes to social diversity with other gestures meant to reassure white southerners, businesspeople, and blue-collar cultural moderates that the party spoke for them too. Today, due to a combination of demographic trends, geographic realignment, and Trump's own behavior, Democratic leaders no longer feel the need to place much emphasis on courting these other voters. By nominating Trump, the Republican Party has bet heavily on a campaign message tailored to appeal primarily to middle-aged, middle-class, middle-American whites. Democrats have opted to make a different wager of their own: that the voters who will feel left out of Trump's vision for America not only represent a rainbow coalition of social groups but also a national electoral majority that can carry Clinton to victory in November.