Over at The Atlantic Online, ace political writer Jack Beatty has an article with a title we like — “The “S” Word Spells Trouble for the GOP: If history is any guide, the Republicans will lose the House this year and the presidency in 2008.” Beatty chews on a few theories of winning elections, and offers some appealing (for Dems) observations:

American politics knows no more certain a predicative metric than that increasing unemployment or rising prices in an election year defeat the incumbent party. The phenomenon is called “economic retrospective voting.” In the long sweep of political history, it appears that, more perhaps than any other factor, the answer to Ronald Reagan’s question in his first debate with Jimmy Carter in 1980—”Are you better off now than you were four years ago?” — decides elections.

Sounds good. And citing an earlier landmark study of voting behavior, Beatty observes:

In “off-years,” when there were no presidential elections, falling real incomes predicted defeat for the incumbent party in statewide races for the U.S. House. For example, a 10 percent decrease in per capita income translated into a loss of 40 House seats.
…In short, either falling real incomes or rising unemployment strongly predicts defeat for the incumbent—that is, the president’s party in off-year elections. If the experts quoted in the Times are right, real personal incomes, which have fallen since 2001, will fall this year—that’s what inflation means. If, to moderate inflation, the Fed raises interest rates to slow the economy, then unemployment will rise. Both are likely to rise together, if Gordon is right, between now and 2008. Thus, if history is any guide, economic retrospective voting should cost the Republicans the House this year and the presidency in 2008

Yep, that’s a lot of “ifs.” But Beatty also points out that:

Correlations between the economy and the presidential vote are weaker than between the economy and the congressional vote…The economy—understood as personal incomes going up or down and unemployment going up or down—is the classic “valence-issue” in politics. “Instead of ‘position’ issues, where one party favors policy X and the other party favors policy Y…’valence’ issues chiefly hinge on perceived government management: my party can manage the economy or the war, for example, better than your party has been doing,” David R. Mayhew, a Yale political scientist, explains in Electoral Realignments (2002). “The more one examines American electoral history, the more it seems to tilt toward valence-issue as opposed to position-issue junctures.” In his 1963 paper introducing the term, Donald E. Stokes defined “valence-issues” as “those that merely involve the linking of the parties with some condition that is positively or negatively valued by the electorate.”

Based on the above, his conclusion makes sense:

If this excursion into political science has any relevance for Democratic electioneering, it may be this: downplay “position-issues”; they leave you open to attack. Instead link the Republicans to “conditions negatively valued by the electorate”—incompetent management of the government and falling real incomes or rising unemployment or both. Make the 2006 and 2008 elections referenda on a record of miserable failure.

Dry, yes. But considering that no such academic studies predicting GOP victories based on historical trends and current indicators are in evidence, Democrats should be be at least cautiously optimistic.