Soon after President Barack Obama’s second inaugural address, Speaker of the House John Boehner said the White House would try “to annihilate the Republican Party” and “shove us into the dustbin of history.”

Actually, the GOP is doing a pretty good job annihilating itself. As Louisiana Gov. Bobby Jindal put it, Republicans need to “stop being the stupid party.”

The GOP crackup was probably inevitable. Inconsistencies and tensions within the GOP have been growing for years.

All President Obama has done is finally find ways to exploit these inconsistencies.

GOP libertarians have never gotten along with social conservatives, who want to impose their own morality on everyone else. Shrink-the-government fanatics have never seen eye to eye with deficit hawks, who don’t mind raising taxes as long as the extra revenues help reduce the size of the deficit.

The GOP’s big-business and Wall Street wing has never been comfortable with the nativists and racists in the party who want to exclude immigrants and prevent minorities from getting ahead. And right-wing populists have never gotten along with big business and Wall Street, which love government as long as it gives them subsidies, tax benefits and bailouts.

Ronald Reagan papered over these differences with a happy anti-big-government nationalism.

But Reagan’s coalition was fragile. It depended on creating a common enemy: communists and terrorists abroad, liberals at home.

In his first term, Obama seemed the perfect foil: a black man, a big-spending liberal and, perhaps (they hissed), not even an American. Republicans accused him of being insufficiently patriotic. Right-wing TV and radio snarled that he secretly wanted to take over America and suspend our rights.

But it didn’t work. The 2012 Republican primaries exposed all the cracks and fissures in the GOP coalition.

The party offered up a Star Wars barroom of oddball characters, each representing a different faction — Bachmann, Perry, Gingrich, Cain, Santorum. Each rose on the strength of supporters and then promptly fell when the rest of the party got a good look.

Finally, desperately, the Republican Party turned to a chameleon, Mitt Romney, who appeared acceptable to every faction because he had no convictions of his own. But Romney couldn’t survive the general election because the public saw him for what he was: synthetic and inauthentic.

The 2012 election exposed something else about the GOP: its utter lack of touch with reality, its bizarre incapacity to see and understand what was happening in the country.

All of which has given Obama the perfect opening, perhaps the opening he’d been waiting for all along.

Obama’s focus in his second inaugural on equal opportunity is hardly a radical agenda. But it aggravates all the tensions inside the GOP. And it leaves the GOP without an overriding target to maintain its fragile coalition.

In hammering home the need for the rich to contribute a fair share in order to ensure equal opportunity, and for anyone in America — be they poor, black, gay, immigrant, female or average working person — to be able to make the most of themselves, Obama advances the founding ideals of America in a way that the Republican Party is incapable of opposing yet also incapable of uniting behind.

History and demographics are on the side of the Democrats, but history and demography have been on the Democrats’ side for decades. What’s new is the Republican crackup, opening the way for a new Democratic coalition of socially liberal young people, women, minorities, middle-class professionals and what’s left of the anti-corporate working class.

If Obama remains as clear and combative as he has been since Election Day, his second term may be noted not only for its accomplishment but also for finally unraveling what Reagan put together. In other words, John Boehner’s fear may be well-founded.