CRAWFORD, Texas - President Bush yesterday signed legislation that extends a popular children's health-insurance program after twice vetoing attempts to expand it.

Politically, the move was a victory for Bush, although Democrats say it will come back to hurt Republicans at the polls.

The extension of the State Children's Health Insurance Program is expected to provide states with enough money to cover those enrolled through March 2009. Bush and some Republican lawmakers say the program will still serve those that it should: children from families who earn too much to qualify for Medicaid but cannot afford private insurance.

Yet many Democrats - with help from some Republicans - wanted to give the program a significant cash infusion and broaden coverage to an estimated four million children. They overwhelmingly supported use of a tobacco-tax increase to pay for the expansion.

The matter came to dominate legislative debate and further sour relations between the Democratic leadership and Bush this year. Twice, Bush vetoed bills that would have expanded the government-provided health insurance for children.