(For other news from Reuters Health Summit, click on http://www.reuters.com/summit/Health14)
By John Whitesides and David Morgan
WASHINGTON, April 2 (Reuters) - A rare burst of good news on President Barack Obama's healthcare program has given Democrats their first glimmer of hope in months on an issue that has helped drag the party down ahead of November's U.S. congressional elections.
A better-than-expected enrollment of 7.1 million people in healthcare exchanges under Obamacare gives Democrats a positive argument to counter relentless Republican calls for repeal of the law, and could help them change the topic to the bread-and-butter economic and job issues Democrats prefer to talk about.
Democrats still face a tough challenge to improve public views of the law, particularly in conservative states where endangered senators like Mary Landrieu of Louisiana and Mark Pryor of Arkansas could face a steep political price at the polls for their support of Obamacare.
Dissatisfaction with Obama and opposition to Obamacare remains strong among core Republican voters, which has helped to crank up their enthusiasm and bolster several strong bids to unseat Democrats who supported the 2010 law.
But now, Democrats say, Republicans will have to make their own political calculation about how hard to push for repeal of a law that will provide health coverage to millions of Americans.
"It's a new ballgame now that people are signed up and getting benefits. This puts Republicans in the position of fighting to take benefits away from people who have them, and that's a tougher argument," said Democratic consultant Doug Hattaway, an aide to Hillary Clinton's 2008 presidential run.
In announcing the sign-ups, Obama declared the debate about repeal was over and "the Affordable Care Act is here to stay." But Republican leaders did not back down, with House Speaker John Boehner saying Republicans would continue their push for repeal.
The enrollment boost followed months of glitches and bad publicity about the law, including the badly botched rollout of the program's prime website, HealthCare.gov.
Republican strategist Ron Bonjean said the law is unpopular enough that the number of people who signed up was irrelevant.
"There is a stigma around Obamacare, and Democrats are not going to get very far arguing that everything is better now," he said. "But the spotlight will probably shine a little less on the issue now that the deadline is passed, so it's important for Republicans to start talking about jobs and the economy."
Democrats plan to make economic issues like Obama's push for an increase in the minimum wage the centerpiece of their message for the midterm elections.
Obama pivoted quickly to the economy on Wednesday, telling a campaign crowd in Michigan that the Republican refusal to raise the minimum wage matched their world view that "basically you're on your own, government doesn't have a role to play in making sure that the marketplace is working for everybody."
He traveled to Michigan with local Representative Gary Peters, a Democrat running for the U.S. Senate at the midterms.
Polls show the Democrats' economic message is far more popular than the healthcare law, which majorities consistently oppose. While a Washington Post/ABC News poll this week showed the law gaining ground slightly, with support at 49 percent to 48 percent opposition, a Quinnipiac University poll on Wednesday showed 55 percent of Americans opposed it.
Representative Steve Israel of New York, head of the committee in charge of electing Democrats to the House of Representatives, said the party would mount a "robust and aggressive" counterattack to spell out that repeal would mean the loss of long-awaited health benefits for the newly insured.
But he was cautious about declaring the enrollment figures had changed the political calculus on the issue.
'TOO EARLY TO SAY'
"It's too early to say whether the tide has turned," Israel said.
Another bout of bad news on the enrollment figures would have been catastrophic for Democratic hopes of holding the Senate, Democratic strategist Chris Kofinis said.
"Had the numbers been bad, it probably would have been a political death knell," Kofinis said. "Now it has gone from a very bad negative to neutral for Democrats. So that helps."
The law and Obama are even more unpopular in conservative states where the battle for Senate control will be fought, as Republicans try to hold power in the House of Representatives and gain the six seats they need for a Senate majority.
Incumbent senators in tough re-election races such as Landrieu, Pryor, Kay Hagan in North Carolina, Mark Begich in Alaska and Jeanne Shaheen in New Hampshire have been attacked for their support of the 2010 law.
Republicans said opposition to the law is a bedrock principle among the party's core voters and will help drive Republicans to the polls.
"When you look at the impact that an issue has on an election, it's all about intensity. The intensity of this issue is very much on the anti-Affordable Care side," Richard Burr of North Carolina, a leading Republican voice on healthcare issues, told the Reuters Health Summit in Washington.
Republicans expect voters to hear about higher insurance premiums for 2015 over the summer and ahead of the November election and predict many who signed up will realize their new plans come with high deductibles and other charges.
"Will that high intensity on the anti-Affordable Care Act side moderate over time? I don't think it will," Burr said.
House Democratic Leader Nancy Pelosi said the benefits of the law extend far beyond the 7.1 million enrolled in the exchanges, and include millions with pre-existing conditions who can now get coverage and others who can benefit from the safeguards against higher premium charges.
Pelosi says the law could also help "defang the issue" for some Republicans who are able to acquire health insurance in times of need because of Obamacare.
"Some of those people will always probably vote Republican. I don't know if this would change their mind. But it certainly will defang the issue for many of them who were so gung-ho one way, until it happened to hit home for them," Pelosi told the Reuters Health Summit.
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(For more summit stories, see ) (Editing by Jim Loney)