WASHINGTON — For the second time in three months, the House failed yesterday to override President Bush’s veto of a bill that would greatly increase spending on a popular children’s health insurance program.

Democratic leaders fell 15 votes shy of obtaining the two-thirds majority needed for an override. The final vote was 260–152, with 42 Republicans siding with Democrats. The result was expected, even as override supporters pointed to the slowing economy as another reason to spend another $35 billion on the State Children’s Health Insurance Program over the next five years.

“Hardworking American families are struggling and in dire need of assistance,” Rep. James Clyburn, a Democrat of South Carolina, said.

But Republicans held strong in their opposition to the spending increase. They said Congress had set aside enough funding to ensure that current SCHIP enrollees could continue their health coverage through March 2009. They criticized Democrats for delaying an override vote to coincide more closely with next week’s State of the Union address from Mr. Bush.

“I think it’s important to highlight that this is simply a political exercise,” Rep. Dave Camp, a Republican of Michigan, said

The legislation that Mr. Bush vetoed would have increased enrollment in the children’s health program to 10 million from 6 million over the coming five years. The revenue needed for that enrollment increase would come from a 61-cent increase in the federal excise tax on a pack of cigarettes, as well as comparable tax increases on other tobacco products.