EVERY four years, Washington moans about the way the national political parties select their presidential nominees. But the grumbling about the 2008 contest has struck an unusual note. Instead of complaining about a process that is too short, some now mutter that the process is too drawn out. Instead of being too predictable, the campaign is too confusing and uncertain: no one has any idea what will happen next. Is this any way to pick a president?

Actually, yes: the Democrats in particular appear to have stumbled  partly by design and partly by chance  into a primary calendar that fixes many of the problems with the way the party has chosen its presidential candidates in the past. Sure, Barack Obama and Hillary Clinton have run extraordinary campaigns. But the framework of the calendar has enriched the competition between them.

Here’s how we got here. In 2000 and 2004, the votes of white men and women in two relatively small states determined the Democratic presidential nominee.

The party’s financiers do not live in Iowa or New Hampshire. Democratic interest groups felt as if their votes and generous donations were being taken for granted. So in 2004, the chairman of the party, Terry McAuliffe, appointed a calendar commission to serve his successor, Howard Dean.