ABC’s Charlie Gibson did a heck of a job advancing the supply-side ball during last night’s Democratic debate. Gibson presented clear evidence that whenever the capital-gains tax rate has been cut in the past twenty years, tax revenues have shot up, while the one time the rate was raised — surprise, surprise — revenues headed south. Gibson then confronted Obama with his promise to essentially double the capital-gains rate if he were elected president. Obama didn’t budge. The reality that a lower cap-gains rate brings in more government tax revenue didn’t faze him one bit. Apparently, nor does the fact that raising the cap-gains rate diminishes jobs, enervates capital formation, and leads to lousy economic growth. Obama’s response and sole concern remains sticking it to rich people, like hedge-fund managers. Someone ought to point out to Sen. Obama that of the 8.5 million tax filers who declared capital gains in 2005, 79 percent had incomes under $100,000. Seventy-nine percent! The unfortunate fact is that Wall Street won’t be the only one hit hard by Obama’s populism. Main Street will be hit even harder. (FYI: John Podhoretz thinks Charlie Gibson has turned into yours truly.)