Massachusetts Sen. John Kerry (search) put off his plunge into the Democratic health care fray, saying he was scrapping a major campaign event to stand up against President Bush's tax cuts.

Kerry had scheduled a high-profile event Thursday at a Des Moines hospital to unveil his $80 billion expansion of the health care system, but instead found himself headed back to Washington when votes were scheduled on the tax cut.

In an interview with The Associated Press, Kerry said the two issues are inextricably linked because the nation can't afford health care reform if big tax cuts force budget deficits.

"The tax bill is so important to all the things we need to do in this country," said Kerry. "It's a fateful decision and I want to be there to make that point."

As a practical matter, Kerry would have found it very hard politically to miss a vote on a tax cut that Democratic presidential candidates routinely attack, particularly since the vote is expected to be close.

"I believe the country wants health care over tax cuts for people who make $350,000 a year," Kerry said.

Aides were scrambling to reschedule the event for Friday, although word of Kerry's health proposal began to leak out.

His plan would expand existing programs to insure children and low-income adults, paying for the effort by repealing some of Bush's tax cuts. He estimates 95 percent of adults and virtually all children would be covered by his plan.

Central to the is an effort to rein in soaring health care costs and cutting into the estimated $350 billion spent each year on the nation's system. The Massachusetts senator argues that administrative waste can be cut in half through "new quality and technology measures."

Among Kerry's proposals is an end to legal provisions that allow drug manufacturers to block generic drugs from entering the market and a requirement that those who manage pharmacy programs disclose any financial incentives they receive from drug manufacturers.

Like former Vermont Gov. Howard Dean (search), Kerry would expand federal and state programs to cover children and low-income parents. He would offer tax credits to help small businesses and uninsured adults buy into the health care program that covers the president and Congress.

"It's paid for by canceling only the Bush tax cuts for the wealthy, while keeping tax cuts for the middle class," Kerry said in prepared remarks obtained by The Associated Press. He did not say what taxes he would keep and what he would repeal.

Kerry aides said the focus on controlling health care costs was a key distinction between his plan and those offered by Missouri Rep. Dick Gephardt (search) and Dean.

In the contest for the Democratic nomination, health care has emerged as an early and defining issue.

Gephardt set the standard by offering a far-reaching proposal estimated to eventually cost $247 billion. His aides suggested that most of the candidates who have since entered the field come up short.

"This is a big problem that requires a big, ambitious solution," said Gephardt spokesman Bill Burton. "The water is 20 feet deep and their plans are 10 feet tall."

Dean has offered an $88 billion package that in some ways resembles the package from Kerry. Spokeswoman Dorrie Clark said Dean, a physician, has a lifetime of experience with the issue.

"Governor Dean is very knowledgeable about health care," said Clark.

Rep. Dennis Kucinich last weekend used an Iowa campaign swing to spell out a plan calling for converting the nation's health care system to a single-payer, government run program.

Sen. Joe Lieberman plans to spell out his proposal later this month.

Democrats see health care not only as a defining issue of the 2004 campaign but a means to score political points against an increasingly popular Republican president and his economic policies. They argue that studies show at least 41 million Americans lack coverage, and some see up to 59 million uninsured.