If Republicans want to figure out why they lost the election, they might start with one number: 36. That’s the percentage of the national electorate represented by white men. Or try 28, the percentage of white men over 30.

John McCain handily won white guys, 57 percent to 41 percent. But he lost badly with other demographic groups he didn’t belong to: youth, minorities and women. The lesson is clear: No party can win a national election depending mainly on voters who are pale, male and gray.

As Jon Huntsman Jr., the Republican governor of Utah, puts it: “We’re fundamentally staring down a demographic shift that we’ve never seen before in America.”

There are many ways to analyze what went wrong for the Republicans, and one lens is ideology. The country did not become more liberal, barely one in five voters accept that label, but moderates swung sharply to the Democratic ticket, 60 percent to 39 percent. Republicans, says GOP pollster Frank Luntz, “basically lost the center.”

Many of these moderates are well-educated suburbanites who fault Republican leaders for overemphasizing some issues (abortion, same-sex marriage) while ignoring others (the environment, climate change). Christine Todd Whitman, the former Republican governor of New Jersey, wrote recently in the Washington Post: “Unless the Republican Party ends its self-imposed captivity to social fundamentalists, it will spend a long time in the political wilderness.”