Republicans were surprised by last week's Supreme Court decision upholding President Obama's health care reforms, but they wasted no time vowing to kill off the Patient Protection and Affordable Care Act themselves.

Repealing the health care reforms will be "the first item on the agenda," Senate Minority Leader Mitch McConnell, R-Ky., promised conservative radio host Laura Ingraham.

But killing off the president's signature legislative achievement will be no easy feat. Indeed, there are so many legislative hurdles to clear that even the most conservative Republicans acknowledge they may not be able to undo the entire law.

"I am not promising a repeal," Sen. Mike Lee, R-Utah, a Tea Party-backed freshman and staunch health care law opponent, told The Washington Examiner.

Republicans scheduled a vote for July 11 to repeal the reforms, but it will be a largely symbolic gesture. Before they can undo the health care law, Republicans must win control of the White House and Senate in November. They're hoping the health care decision itself will aid their election efforts by rallying their voters and bolstering their candidates.

Mitt Romney, the presumptive Republican presidential nominee, trails Obama in swing-state polls. But the Republican Party hopes the court's determination that the health care law amounts to a tax will help Romney gain on Obama. Romney already reaped benefits from the ruling, pulling in $4.6 million from 47,000 contributors within 24 hours of the court's announcement, spokeswoman Andrea Saul said.

Most political analysts expect Republicans to hold their majority in the House, but things are far less certain in Senate, where several seats remain tossups.

Democrats are clearly worried that the health care decision could hurt in their Senate races. Tim Kaine, the Democratic Senate candidate in Virginia, warned supporters that he needed more money if he was going to help prevent Republicans from taking over and repealing the health care reforms.

"In the wake of yesterday's health care ruling, the stakes have gotten much higher, and it's easy to see why," Kaine wrote. "George Allen says he wants to be the 51st vote to repeal the health care law; I want to be a vote to improve it."

Even with full control of Congress and the White House, Republicans face legislative hurdles in trying to repeal the law. Full repeal would require 60 votes in the Senate, and neither party is expected to hold that many seats after November.

Republicans could repeal some -- but not all -- of the reforms with just 51 votes. While such budget reconciliation votes only affect reforms that involve federal spending, they would still allow the GOP to change major provisions of the law.

"There is a lot we can do with 51 votes," Lee told The Examiner.

The law's requirement that Americans buy health insurance was declared a tax by the court, and that made it eligible for repeal with just 51 votes. And a simple majority is all that's needed to strike the law's expansion of Medicaid as well as the federal subsidies that would be paid to help people buy insurance, according to Joseph Antos, a health care scholar at the American Enterprise Institute.

"While you can't get rid of the whole law," Antos said, "you can get rid of most of it through reconciliation."