After John McCain’s defeat, even amateur political analysts could see a trend ultimately fatal to the Republican Party.

Ninety percent of McCain voters were white, and 90 percent Christian. But Christians have fallen to 75 percent of the population and are sinking, and white Americans have fallen to 66 percent of the population and are headed for minority status by mid-century.

The handwriting is on the wall. Soon, even GOP sweeps of two-thirds of the white vote that Richard Nixon and Ronald Reagan managed will not be enough to capture the presidency. And as the GOP base contracts, the Democratic coalition—due to mass Third World immigration, anchor babies and higher birth rates—steadily expands.

Yet, within the Barack Obama coalition—over 60 percent of Asian-Americans, 68 percent of Hispanics, 78 percent of Jews, 95 percent of blacks—fissures and fractures have become visible, not only along racial and ethnic lines, but along issue and ideological lines.

“The high-profile Florida Senate race” between Gov. Charlie Crist and Tea Party favorite Marco Rubio, writes The Washington Post, “has evolved into a battle that is tearing apart Democrats.”

How so? Florida Democrats nominated Kendrick Meek, the only African-American with a shot of sitting in the U.S. Senate in 2011. While Meek’s chances remain slim, Al Gore has gone in for him, and Bill Clinton and Barack Obama are coming, in the name of party solidarity.

However, Meek’s former House colleague, Robert Wexler, who represented Palm Beach County while Meek represented Broward, has “all but ordered the state’s many Jewish voters to back Crist.”

Should Meek lose because Jewish Democrats, on Wexler’s orders, cut him dead for Charlie Crist, black bitterness at this betrayal of their only hope for a U.S. senator will be off the charts.

What is Wexler thinking?

Black-Jewish tensions inside the Democratic coalition have also arisen in recent years, as Jewish contributors have poured money into races to defeat black members of Congress seen as hostile to Israel.

Two smaller minorities, Muslim- and Arab-Americans, also vote Democratic, are growing rapidly in numbers and, like many African-Americans, take the side of the Palestinians as an oppressed Third World people of color.

Yet, this is by no means the only fracture.

Proposition 8, the California referendum to outlaw same-sex marriage, won the support of a majority of Hispanics and 70 percent of African-Americans. Black preachers implored their congregations to march to the polls and vote down the abomination of homosexual marriage, which gays, lesbians and liberals regard as the great civil-rights cause of our era.

On social issues like abortion, Hispanics and blacks, two of the most churched peoples in America and the most deeply religious in the Democratic coalition, regularly vote against white liberals.

Yet, African-Americans at 40 million and Hispanics at 50 million, now living side-by-side in the cities, also clash over spoils and turf. In New Orleans, black majority resentment at Mexican workers coming in and taking the jobs rebuilding the city spilled out into public acrimony.

In California, Hispanic and black gangs are engaged in what one sheriff calls “a civil war of the underclass.” In U.S. prisons, black-white violence now takes a back seat to black-Hispanic violence.