Creating a tax deduction to spur sales of clean-fuel vehicles - which the IRS now says include gasoline-electric hybrids - was bad enough. Enacting a tax credit primarily for buyers of hybrids and fuel cells would be foolish.
It is perilous to use the tax code to implement selective social policy.
Any incentives ought to be for fuel economy, however it is achieved, whether by good engineering of the car and powertrain or by new technology such as hybrids, electrics and fuel cells.
Under the proposal, a hybrid Dodge Durango that gets, say, 25 mpg could get a big tax credit while a really efficient gasoline- or diesel-powered Honda Civic or Ford Focus could get 50 mpg but no tax credit. Go figure.