In a decade that has produced precious little good news about health care and health insurance, one of the remarkable success stories is a federal-state partnership known as the State Children's Health Insurance Program. Since its creation in 1997, SCHIP has cut the number of uninsured American children by one-third, generally at low cost and generally in a way that governors could tailor to local needs.

Reauthorizing the program, which expires this fall, should have been easy. Bills emerged in both chambers of Congress with bipartisan backing and more than 30 governors, Republicans and Democrats, wrote letters of support.

So it's a mystery why President Bush has chosen SCHIP for a veto showdown with Congress, a threat he renewed with great vigor just last week. It's important that senators stick to their guns and let the White House know a veto will be overridden.

When Bush first signaled his qualms about the program last spring, he raised legitimate questions. He said the House version could cause "crowding out" — encouraging families to drop private insurance to get public coverage — and said it would extend subsidies to families earning as much as $80,000 a year.

But last month the Congressional Budget Office weighed in with an analysis of the Senate's SCHIP proposal. It said two-thirds of the children who would gain coverage really would otherwise go uninsured — meaning an extremely low crowd-out rate compared to other government subsidies — and that 85 percent would fall under existing, tough state definitions of the poor and near-poor. As for the $80,000 number, Republican Sen. Charles Grassley of Iowa politely said the president simply had his facts wrong.

Speaking last week, Bush raised a third concern — that a new SCHIP compromise based on the Senate bill, costing $35 billion over five years, would break the federal budget. That's a peculiar charge coming from a president who is about to ask Congress for an additional $200 billion for Iraq and Afghanistan, all of it financed through federal borrowing. But in any case, it's wrong: This bill is fully paid for with a tobacco tax that would have the additional benefit of reducing smoking.

SCHIP has won bipartisan support in Congress because it offers sensible, preventive care for children using efficient, private providers suited to local needs. That should be enough to win the president's support too.