Michael Barone applies his electoral number-crunching expertise to an exploration of the Democratic Party’s coalition of voters. The results of Barone’s analysis appear at National Review Online.

John Judis, co-author of the book The Emerging Democratic Majority, now says in an article in National Journal that that majority has disappeared. His title: “The Emerging Republican Advantage.”

The original book, published in the Republican year of 2002, forecast accurately the groups that would make up the Democratic majority coalition that emerged in the 2006 and 2008 elections: blacks, Hispanics, gentry liberals, single women, young voters.

But as Judis writes now, that coalition has come apart. That’s partly because of diminished support from Millennials and Hispanics, but mostly because of additional white working-class defections and erosion among suburbanites unhappy with higher government spending and taxes.

In fact, he now says that the majority he predicted endured for only two elections. President Obama was re-elected with a reduced 51 percent of the vote, but Republicans won the House in 2010, 2012, and 2014, and the Senate in 2014. Democratic strength in governors’ mansions and state legislatures is at its lowest level since the 1920s.

That’s in line with voting patterns that have been steady for two decades. In three of the last four presidential elections, both parties have won between 47 and 51 percent of the vote. And in nine of the eleven House elections from 1994 to 2014, Republicans won between 48 and 52 percent of the popular vote, and Democrats a bit less, between 45 and 49 percent.