Those who consider themselves constitutional conservatives should take care to consider not only the powers that the Constitution confers on the different branches of government and reserves to the states and the people, but also the schedule that the Constitution sets up for sharp changes and reversals of public policy.
The entire House of Representatives is elected every two years. The voters in 2010, with unusual clarity, elected a House determined to reverse the Obama Democrats' vast increase in the size and scope of government.
But determination is not enough. Barack Obama, elected in 2008, remains in office, armed with a veto. The friendly mainstream media permit him to use euphemisms to insist on tax increases that were roundly rejected by the voters in 2010.
And the Senate, two-thirds of which was elected in the Democratic years of 2006 and 2008, retains a Democratic majority that, though unable to pass its own budget, can frustrate House Republicans' attempts to deliver on their more recent mandate.
The lesson is that you have to win at least two elections in a row to make the kind of policy changes that the Obama Democrats made in 2009 and 2010 and that House Republicans want to make now.
The good news for Republicans is that there has been a convergence of voting in congressional and presidential elections.
Starting in the 1950s, accelerating in the '60s and '70s, and continuing in the '80s, many Americans split their tickets, often electing Republican presidents but electing Democratic House majorities for 40 years.
In the middle 1990s, that changed. The Democratic percentage of the vote for president and for the House of Representatives have differed by no more than 1 percent starting in 1996.
In addition, the percentages for the two parties in the popular vote for the House in the last three off-year elections have been almost exactly the same as the percentages for the parties in the vote for president two years later.
In 1998, the popular vote for the House was 49 percent to 48 percent Republican. In 2000, the popular vote for president was 48 percent to 48 percent Democratic.
In 2002, the popular vote for the House was 51 percent to 46 percent Republican. In 2004, the popular vote for president was 51 percent to 48 percent Republican.
In 2006, the popular vote for the House was 53 percent to 45 percent Democratic. In 2008, the popular vote for president was 53 percent to 46 percent Democratic.
Obviously, this is not good news for Barack Obama, since the popular vote for the House in 2010 was 52 percent to 45 percent Republican. Translate those numbers into electoral votes, and you have something like a 331 to 207 Republican victory.
Now it is possible, even in a period when the congressional and the presidential vote have converged, for a president to improve on his party's off-year performance. Bill Clinton did so in 1996, running 5 percent ahead of his party's House performance two years before, by sharply changing course on public policy.
And it seems that in the negotiations on the debt limit, Obama is trying to depict himself as following a similar course.
He has said he would support billions in spending cuts -- though without providing any specifics. He has said that he would be willing to "look at" means-testing Medicare -- though it's unclear this commitment amounts to anything.
He has encouraged the pliant press to depict Republicans' opposition to "revenues" -- translated into English that means tax increases -- as "intransigence."
But it's Obama who has been intransigent about insisting on tax increases that voters endorsed tepidly at most in 2008 and that they clearly repudiated in 2010.
Obama promised to fundamentally transform America, and he and his party have managed to increase the federal government's share of gross domestic product from 21 percent to 25 percent -- a huge policy change. They are striving now to keep it at that level permanently.
Republicans want to reverse that enormous policy change, and many are ready to denounce any debt limit deal that leaves them short of that goal.
Before doing so, they ought to consult the Constitution. To achieve the changes they want and that voters endorsed in 2010, they need to win again in 2012. The deal that gets them closer to that is what they ought to be seeking now.