Yet since Ronald Reagan departed and George W. Bush arrived, that coalition has been under a growing strain that may yet pull it apart and redefine what conservatism means in 21st century America.
Is a free-trade globalism that saw America lose 57,000 factories and 6 million manufacturing jobs in the last decade conservatism?
From Abraham Lincoln to Teddy Roosevelt to Calvin Coolidge, that was once economic treason.
Was invading Iraq, which never threatened us, consistent with conservatism? Was a decade of nation-building in Afghanistan something Reagan would have pursued? These neo-imperial wars would have bewildered our founding fathers.
A new clash is ahead that seems fated to split the right into fiscal hawks versus security hawks. It was scheduled for early 2012 by the debt-ceiling deal forced on Barack Obama by Tea Party Republicans.
That deal cuts spending $900 billion in 10 years, with defense cuts coming in at $400 billion. The Pentagon is already at work.
Beyond that, if the new bipartisan, bicameral deficit-and-debt-reduction super-committee of 12 fails to come up with $1.5 trillion in added spending cuts and/or tax revenues, Congress must vote in 2012 to achieve $1.2 trillion in cuts.
And half of that, $600 billion, must come out of defense.
Can the super-committee avoid these defense cuts by coming up with the $1.5 trillion by Thanksgiving, which would have to be approved in up-or-down votes in both houses by Christmas?
Highly improbable, if not politically impossible.
Consider: Should the super-committee vote for new tax revenue, John Boehner's House would reject it, as the House threatened to shut down the government rather than permit higher taxes in the debt-ceiling deal.
Yet if there are no new taxes in the $1.5 trillion deal, Harry Reid's Senate would reject it, for that would be a second humiliating defeat for the left, fomenting open rebellion against Reid.
Some in Washington are saying the super-committee was set up to fail. Sen. Mitch McConnell has already said no Republican open to higher taxes will be named to the GOP's six-member slate.
Thus, in the first major step in a decade-long drive to roll back Big Government, the Pentagon will likely have to contribute $1 trillion, or 8 percent of anticipated defense spending.
And this is only the beginning. For even after the debt-ceiling deal, projected deficits are so huge that a downgrade of the U.S. debt rating and eventual default, even if done through inflation and depreciation of the dollar, seem certain.