Supporters of tax credits for private school tuition in South Carolina continue to show their stripes.

They recently sent letters to a newspaper under a bogus name. They are trying to intimidate political action committees and state legislators with threats aimed at punishing any Republican who stands against the controversial tax plan.

This comes after the leading organization behind the "Put Parents in Charge" bill referred to state Superintendent Inez Tenenbaum on its Web site as "Frau Tenenbaum."

These are the people who are spending millions of dollars from out-of-state ideological organizations, all under the guise that they are suddenly smitten by an urge to see that poor children in South Carolina can get ahead. It's a thin guise.

They are the ones trashing public schools, insulting hundreds of thousands of children, parents, teachers, principals and administrators who are actually on the front line offering poor children -- and all children -- a better future if they'll take it.

They refer to public schools as "monopolies" and those who work there as selfish bumps on a log. But public schools are not monopolies, and children are not commodities. Public schools already have plenty of competition. The free market system in education is already alive and well. And parents are already in charge.

Taxes to support public schools are not user fees. Sound public schools are the measure of any community and any society. It is to everyone's benefit that the public schools prosper. Would we sit still as out-of-touch ideologues undercut the local fire department or police department because they are "monopolies"? Of course not; that's preposterous. And so is this slick new push to slander the public schools and give financial rewards to anyone who will leave them behind. It is a failed mindset.

Beneath all the rhetoric by Gov. Mark Sanford and supporters of his tax-credit scheme is a simple, basic truth:

South Carolina cannot afford this plan. It is not a school plan, but a tax plan. It would remove from the state's General Fund hundreds of millions of dollars needed for basic government services, including Medicaid for the poor. It would enable corporations or individuals to get a dollar-for-dollar tax write-off for donations to scholarship organizations, so the total hit on the state General Fund cannot even be measured. It is bad fiscal policy, especially as the state's bond rating is already being questioned due to the governor's proposed income tax cut.

Many people doubt that poor people could afford private school, even with the tax breaks. And that assumes the private school would accept the students and that they could get to those schools without bus service.

The nuts and bolts of this proposal don't add up, and neither does the ideology. It's no wonder the proponents are overlooking the state's landmark Education Accountability Act of 1998, which is showing steady improvements in the classroom. And it's no wonder they feel they must resort to name-calling and intimidation. Don't fall for it.