[cnn-photo-caption image= http://i2.cdn.turner.com/cnn/2010/images/07/03/art.steelecu0703.gi.jpg caption =" RNC Chairman Michael Steele is touting a primary result in Missouri where voters rejected a key provision of the new health care law."]Washington (CNN) - National Republicans are touting a primary result in Missouri where voters overwhelmingly rejected a key controversial part of the new health care law. But Democrats downplay the significance of the vote, the first in which the new health care law was on a ballot.
More than 70 percent of Missouri primary voters Tuesday cast ballots in favor of Proposition C. The measure would allow state residents to opt out of mandatory health insurance, a key part of the new health care reform law, which was pushed by President Obama and Congressional Democrats. The proposition prohibits the federal government from requiring people to have health insurance or penalizing them for not having such insurance.
"In a significant blow to the Obama administration, the people of Missouri overwhelmingly struck down a central pillar of ObamaCare by passing a statute that prevents the federal government from requiring individuals to purchase health insurance," says Republican National Committee Chairman Michael Steele, in a statement. "By rejecting ObamaCare with nearly three-quarters of the vote in a critical swing state, Missouri sent a clear message to Democrats and the Obama administration that government-run healthcare is a gross overreach of the federal government that needs to be repealed and replaced."
In a full court press, the top Republicans in the Senate and the House released similar messages.
"All throughout the health care debate, Democrat leaders in Washington told themselves they could do what they want, and then persuade Americans after the fact that it was okay. Last night, the voters in Missouri overwhelmingly rejected that notion. The people of Missouri have sent a message to Washington: enough is enough," says Senate Minority Leader Mitch McConnell of Kentucky.
"There is one constant in the story of ObamaCare: the steadfast opposition of the American people to out-of-touch Washington Democrats' plan," adds House Minority Leader John Boehner of Ohio.
More Republicans than Democrats appear to have voted in Tuesday's primary. According to unofficial results compiled by the Associated Press, 577,612 ballots were cast in the GOP Senate primary, compared to 315,787 cast in the Democratic Senate primary. On Proposition C, 938,782 people voted, with 71 percent in favor of the measure and 29 percent opposed.
Democrats have a very different take on the primary vote.
White House Press Secretary Robert Gibbs Wednesday described the Missouri results as "a vote of no legal significance in the midst of heavy Republican primaries"
"It's essentially meaningless – there was a hotly contested Republican primary, and those voters were the ones voting on this. Also, it has no legal significance – and Democrats didn't pay any attention to it or even run a campaign against it because of it," a Democratic source tells CNN.
Since federal law generally trumps state measures, the fate of Proposition C will most likely be decided in court.
"Ultimately the courts are going to have to decide about states rights and federal authority when it comes to the Obama health care law. For now this is no more than another Republican talking point to use to energize voters for November and to try to keep the Democrats on the defensive," says Stuart Rothenberg, editor and publisher of the non-partisan Rothenberg Political Report.
But Republicans say Tuesday's vote is a sign of things to come in the upcoming midterm elections, when the Democrats will try to defend their majorities in both houses of Congress and their lead among governorships.
"Last night's decisive vote against a key provision of ObamaCare, arguably the cornerstone of the Obama presidency, shows how completely detached the Democrat agenda is from the American electorate, and is another reason why Republicans will win back the majority in November," adds Steele.
Americans appear to be divided on the overall law. According to a CNN/Opinion Research Corporation national poll released last week, the public's split on lawmakers should repeal the new law and replace it with new proposals.
–Follow Paul Steinhauser on Twitter: @psteinhausercnn
–CNN Congressional Producer Ted Barrett contributed to this report
Updated: 3:21 p.m.