Republicans on Wednesday trumpeted a Missouri referendum approved by voters that rejected a key part of President Obama's signature healthcare reform law.

Top GOP lawmakers and Republican National Committee (RNC) Chairman Michael Steele acclaimed a ballot initiative in the Show-Me State that exempts residents from insurance mandates contained within the healthcare reform bill Obama signed into law in August.

"Last night, in Missouri, they sent a message as loud as it was clear," said House Minority Leader John Boehner (R-Ohio). "By a more than two-to-one margin, they don’t want the unconstitutional mandate at the heart of ObamaCare."

Missouri voters approved the initiative with just over 71 percent in favor of the ballot language, which looks to exempt residents from the new rules requiring individuals to have health insurance, and also businesses, which have to provide health insurance options to employees or face stiff penalties.

"The voters of Missouri sent a clear message that the federal government has no business forcing people to buy health insurance against their will," Senate Minority Leader Mitch McConnell (R-Ky.) said in a floor speech on Wednesday morning. “And I applaud them for it."

Republicans' excitement over the vote reflects a sense that Missouri, traditionally a swing-state in elections that's seen as a bellwether on a number of political issues, could spell greater success for the GOP's election-year promise to repeal the Democratic-led health reform, and replace it with new reforms.

Steele drew a direct connection between the Missouri vote and Republicans' optimism for this fall's midterm congressional elections.

"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," he said.