Democrats attending the party's national convention in Denver downplayed the latest U.S. Census figures showing the number of people without health insurance dropped last year for the first time since the Bush administration took office, saying the gains are dwarfed by the number of uninsured remaining.

The U.S. Census Bureau reported Tuesday that the number of people lacking insurance dropped by more than 1 million in 2007 -- from 47 to 45.7 million.

"It's down a million. I think it's great for those million who got it, but I think it's meaningless in the sense there's still 46 million people who don't have any health insurance in this country," said Terry McAuliffe, former chairman of the Democratic National Committee.

Universal health care is a central theme in the Democrats' platform, with Sen. Ted Kennedy, a longtime advocate, telling delegates Monday night at the Pepsi Center that he is resting his hopes for such a program on Barack Obama's winning the White House.

McAuliffe said national health care is the No. 1 priority.

"We're the greatest country in the world. We ought to be able to deliver health care to everybody at an efficient cost," he told FOXNews.com. "I promise you within the first year with Barack Obama as president of the United States ... we're going to have national health care."

Obama, who is campaigning in swing states before heading to the convention, released a statement saying the Census report "confirms what America's struggling families already know -- that over the past seven years, our economy has moved backwards."

The statement focused on the Census finding that the poverty rate nevertheless held steady in 2007 at 12.5 percent -- about the same as the 12.3 percent rate in 2006. That translates to 37.3 million in poverty in 2007.

Obama dismissed the drop in the number of uninsured, saying during the Bush administration as a whole, "an additional 7.2 million Americans have fallen into the ranks of the uninsured. This is the failed record of George Bush's economic policies that Senator McCain has called ‘great progress'."

California Sen. Barbara Boxer told FOXNews.com she's skeptical of the statistics, since they don't reflect the economic downturn this year.

"I hope it's true that people still have more insurance ... but in my state we're in recession," she said. "So that's a little bit old news, and I hope it's true, but I'm nervous about the future."

Boxer said the drop in the number of uninsured may have been due to sign-ups in the military and accompanying health care plans, as well as enrollments in the State Children's Health Insurance Program, which provides health care to children. She chided President Bush for vetoing a massive expansion of that program in 2007.

"All I can say is I hope this is true in the next report," Boxer said.

FOXNews.com's Judson Berger and The Associated Press contributed to this report.