"We are at the end of the Reagan era." Or, at least, that is the claim of voices as diverse as Newt Gingrich and Ed Rollins on the right and Sen. Chuck Schumer and pollster Stanley Greenberg on the left. It is true the Republican Party is having difficulty retooling its message for the 21st century. But so is the Democratic Party.

Every presidential election is about change, and no more so than at the end of a two-term president's time in the White House. Parties have to constantly update themselves if they hope to remain relevant. The difficulty for both Republicans and Democrats is that our political system is at a point where more than the normal amount of party growth and development is needed. Both parties are suffering the consequences of seeing substantial parts of their 20th-century agendas adopted; both parties are struggling to fashion new answers to the new challenges of a young century.

But that's not to say that the Reagan legacy is exhausted. Ronald Reagan's legacy was not simply that he was "a campaigner and orator of uncommon skill," as Don Campbell argued last week in USA Today. President Reagan's gifts to the Republican Party were ideas: growing the economy through tax cuts, limiting government's size, forcefully confronting totalitarian threats, making human rights a centerpiece of America's foreign policy, respecting unborn human life, empowering the individual with more freedom. Those ideas endure. They give Republicans a philosophical foundation on which to build. The Reagan coalition has a natural desire to stick together. Fiscal, defense and values conservatives have more in common with each other than with any major element of the Democratic Party's leadership.

Democrats have a similar philosophical storehouse in the ideas of FDR and LBJ. Both expanded the size and scope of the federal government and saw it in almost an entirely positive light: as an agent of economic redistribution from the rich to the less affluent, as a provider to the poor and the disabled and as an enforcer of equal rights and equal justice. The Democratic Party has two challenges. One is that the modern economy has led voters to prefer markets, decentralization and consumer choice far more than centralized control by government and the substitution of "expert" decisions for those of the individual. The other challenge is that many in that party mistake the "Third Way" tactics of the Clinton years for a substantive approach to governing. Triangulation--making yourself look good at the expense of allies and adversaries in both parties--is lousy for providing coherent answers to modern issues.