Over at Balkinization, Jack Balkin argues that the George W. Bush presidency "destroyed Reaganism":

Bush has . . . overseen the cracking of Ronald Reagan's successful coalition of southern former Democrats, white working class ethnics, defense hawks, free market conservatives, and religious conservatives. Reagan could appeal to all of these elements of the party, but Bush's Presidency has been unable to keep all of them happy. Had Bush's war on terror (including the Iraq war) been successful, he might have kept most of the coalition together even though he simultaneously increased the size of government, downplayed coded racial appeals that brought in the South, supported immigration reform, ran up large deficits, and offered only modest and symbolic achievements to religious conservatives. But his policy failures made this impossible.

Bush's failed presidency has left the Republicans scrambling to reconstitute the Reagan coalition. The wide range of different candidates-- from Giuliani to Romney to McCain to Huckabee to Paul-- offer different solutions. We don't yet know how the coalition will be reassembled, and under whose leadership. However, as of the day of the New Hampshire primary, it looks like putting it back together will be a tall order. And although the eventual nominee will try to assume the mantle of Ronald Reagan-- and, equally important, not the mantle of George W. Bush-- the Republican party will have been changed forever by the events of the last eight years.

Although Ronald Reagan will still be regarded with fondness by the Republicans for generations to come, George W. Bush will have effectively destroyed Reaganism. The Republicans will have to start over with a different mix of concerns, agendas and appeals. This is George W. Bush's single greatest achievement. This is one reason, although not the only reason, why he ranks high (or low) among the country's failed presidents-- not only did his policies fail, but he also took the winning coalition that brought him into office down with him.

And that is why, if, like many Americans, you think that change is coming, and you think that this is a good thing, you should tip your hat to George W. Bush and his eventful presidency. For if Ronald Reagan was the Great Communicator, George W. Bush is the Great Destroyer of Coalitions.

  I am a law professor, not a political analyst, but I tend to disagree. To be sure, Bush's many unforced errors over the last seven years is hurting the Republican nominees. But Bush's unpopularity hasn't "destroyed Reaganism." To the contrary, it seems to have made the Republican party more committed to Reagan's ideas and coalitions and more suspicious of alternatives. Indeed, all of the Republican candidates are clamoring to be considered the next Ronald Reagan. While some of the candidates struggle to do this, that's a reflection of their personal limitations rather than a lack of interest within the GOP in Reagan's approach and ideas.

  Time will tell how these things will play out, and anything can happen. At the same time, I tend to doubt that the Bush Presidency will cause a long-term shift in the major coalitions and ideas driving the GOP.