Bloomberg, good for the Democrats? First Read, the blog of the NBC News political unit, speculates that a Michael Bloomberg presidential candidacy would help the Democratic nominee in November 2008: “Why? It’s simple — the South. The irony of a Bloomberg candidacy is that it could make the Democrats more competitive in the South because their 35 percent base vote in the South is made up of die-hard Democrats.”

The Bloomberg-helps-the-Dems argument presumes that Bloomberg’s appeal will resemble Ross Perot’s in 1992, notes The Atlantic’s Marc Ambinder. “Perot managed to sap as many liberal independents from Democrats as he did conservative independents from Republicans,” Ambinder writes. “But Bill Clinton’s base was solid enough in the South; more solid than the Republican base. Perot’s other demographic strongholds included younger voters, unmarried Midwesterners, rural voters, evangelicals and protestants.”

But Bloomberg’s appeal is not very similar to Perot’s, as Ambinder explains. He writes:

Perot appealed to downscale Reagan Democrats, to economic populists, to opponents of NAFTA and free trade. He tapped into a vein of populist discontent with both parties, but particularly those branches than ran through Republican arteries once Bush abandoned his no-tax pledge. His technocratic appeal — “I’ll do what works; I’ll balance the budget” — stole a page from the G.O.P. The foreign policy debate was mostly about the peace dividend; it did not, as it does now, overshadow the domestic political environment.

Bloomberg wants something different. He’s hinted at broad, programmatic solutions to intractable problems. He is, at the same time, a cultural liberal with an anti-libertarian streak; ask any New Yorker who smokes, or who enjoyed their trans-fats [cheeseburgers] whether Bloomberg left them alone. Health care, education, the environment — Democrats have an enormous edge right in attracting voters who care about these issues. If Bloomberg somehow offers an alternative, it’s not hard to suppose that many Dem-leaning independents will be attracted to his candidacy.

Point two: independents are overcommitted to Democrats right now, giving them as much as 70 percent of their generic presidential support in certain surveys. A conservative Republican candidate wouldn’t attract too many independents anyway, in theory, and Democrats have many independents to spare, and lose. Why assume that Bloomberg wouldn’t take more votes from the Democratic candidate?