Washington (CNN) -- Now that the House has passed the Senate's health care reform bill and a package meant to reconcile differences between the House and Senate bills, the next step is for members of the Senate to sign off on those changes.
That won't be as easy as it sounds.
Senate Republicans have indicated they will use any and all legislative tactics in order to slow -- even stop -- the reconciliation bill from passing.
President Obama is expected to sign the health care bill Tuesday at the earliest. Only then can the Senate begin dealing with the reconciliation package.
According to Senate rules, members are allowed to offer unlimited amendments and challenges to the reconciled bill.
"There's hope that [the vote] would be done within a short period of time, like a week or so," said Tim McBride, a health economist and associate dean of public health at the Brown School at Washington University in St. Louis, Missouri. "But the Senate is complicated and doesn't have the discipline that the House does."
Once the bill hits the Senate floor, reconciliation rules stipulate that there must be 20 hours of debate.
But that 20 hours is more of a suggestion than an indicator of what will happen, because Republicans are allowed to offer unlimited amendments and are geared up to offer many, all of which must be ruled on by the Senate parliamentarian.
"It could get all messy and could go on forever if they threw up amendment after amendment," said Cheryl Block, a law professor at Washington University's School of Law. "Theoretically, it should only take 20 hours, but it will likely take longer because Republicans have things up their sleeve."
Senate Democrats, though, do have an option to overrule the parliamentarian's decision; but they would need Republican votes to reach the necessary three-quarters majority required to do that, and that's unlikely in the highly polarized Senate.
Meanwhile, if a provision in the reconciled package is struck down, the bill would then have to go back to the House for another vote.
House Democratic leaders are hopeful they will have enough support in the Senate to stop Republicans' attempts to block the legislation. All they need is a simply majority of 51 votes. If needed, Vice President Joe Biden, who serves as president of the Senate, could cast a tie-breaking vote.
Ahead of Sunday's vote, House Speaker Nancy Pelosi said she was confident the reconciled bill would receive the Senate's backing.
She said that when her members go to vote, they will have "all of the assurance they need" that the reconciliation package will be passed in the Senate.
"When we bring the bill to the floor, we will have a significant victory for the American people," Pelosi added.
House Minority Leader John Boehner, however, argued Friday that the vote was "pretty tight."
Boehner had said the revised health care bill was worse than the original legislation, adding that the "American people are going to hear about every payoff, every kickback and every sweetheart deal that comes out."
CNN's Evan Glass and Kristi Keck contributed to this report.