Two sets of numbers tell you a lot about an important difference between election year 2008 and election year 2010.
In 2008, 37 million Americans voted in Democratic presidential primaries and just under 21 million voted in Republican presidential primaries. One reason for the difference was that the Republican nomination was decided earlier. But even counting only the early contests, Democratic turnout was 26 million and Republican turnout was 17 million.
This year, it's different. Only 13 million Americans have voted in Democratic primaries held before Sept. 1, according to Curtis Gans of the Center for the Study of the American Electorate. During the same period, 17 million voted in Republican primaries.
As Gans points out, that's historic. Democratic primary turnout has been higher than Republican primary turnout in every off-year election since 1930.
That Republican margin may narrow a little as the returns from this week's primaries come in from states like New York, Massachusetts and Maryland, which have a lot more registered Democrats than registered Republicans. Yet in California, where Democrats have a similar registration edge, almost as many Republicans showed up as Democrats.
What we're seeing here is a change -- a sea change -- in the balance of enthusiasm. That's been critical in a decade in which turnout in presidential years increased from 105 million to 122 million to 131 million. Republicans had a narrow advantage in the balance of enthusiasm in 2002 and 2004. Democrats had a wider advantage in 2006 and 2008. Now Republicans clearly have a wide advantage and have a good chance to sweep the elections six weeks and six days from now.
Democratic strategists hope that Barack Obama can rekindle some of the enthusiasm that was so apparent two years ago. Liberal columnists have cheered his slashing attack on House Minority Leader John Boehner and his denunciation of proposals to maintain the tax cuts on those earning more than $250,000.
I doubt that it will be that easy. Enthusiasm is not aroused simply by a stirring speech. It's aroused by seeing your ideas and policies work out the way you expected. Or, perhaps even more, it's aroused by seeing your political adversaries' ideas and policies fail to work out the way they expected. In that case, you're usually pretty sure your alternatives will work out better -- and you're enthusiastic about trying them.