The abortion issue has been vexing for Democrats in the House. Rep. Bart Stupak, an anti-abortion Democrat from Michigan, pushed for measures in the House bill to which pro-choice Democrats were opposed.

Drucker said Democratic factions in the House will make it tough for the bill to move forward, adding "the Senate abortion language doesn't satisfy [conservative Democrats]."

But in the end, it's about the vote count, a congressional expert said.

"My sense is there aren't enough votes in the House to pass the Senate-passed bill," said Craig Volden, a professor of political science at Ohio State University. "It's not clear what bill would pass the House that would also get 50 votes in the Senate, even if they went with reconciliation."

Volden said the House and Senate will be hesitant to vote on anything they don't think will go all the way through to final passage.

And on the issue of the public option, liberal Democrats in the House and Senate still hope it will be included in the final bill even though it's not being supported by the president.

Recently, a group of 30 Senate Democrats indicated its support for keeping a public option in the bill. Some of those Democrats include Senate Majority Whip Dick Durbin, along with Sens. Jeff Bingaman, Ben Cardin, Amy Klobuchar and Chuck Schumer.

But House Speaker Nancy Pelosi, a vocal supporter of the public option, has admitted it would not be in the final bill.

Asked about the White House's decision to not include the public option, Gibbs has said the decision was made because it did not appear that there would be sufficient votes to get the public option passed in Congress.

Another issue for Democrats in using reconciliation: The 2010 midterm elections.

With polls showing opposition to the Senate's health care reform bill, many conservative Democrats up for re-election are worried that voters will push them out in November.

King, who also serves as the faculty director of Harvard's program for Newly Elected Members of the U.S. Congress, said Democrats' "base calculation is probably political."

"The Scott Brown election [in Massachusetts] has -- in the minds of many members -- changed their re-election calculations."

Some Democrats may be especially concerned about accusations from Republicans that they short-circuited the legislative process.

Republicans are already seizing on Democrats' worries.

Sen. Lamar Alexander, R-Tennessee, said that if the bill passes through reconciliation, a new set of headaches begin for Democrats.

"Then for the rest of the year," he said on ABC, "we're going to be involved in a campaign to repeal it."

Democrats have faced a large pushback from Republicans on the issue. House Minority Leader John Boehner has even gone so far as to call for both bills to be scrapped and for Congress to start over. Should Democrats use reconciliation, Republicans will more than likely use it against them.

But the White House is calling Republicans out, noting that every Republican senator who took part in last week's health care summit has voted in the past for a reconciled bill.

Nonetheless, Republicans have said that using that parliamentary procedures for a health care reform bill can't be justified.

"Just because it has been used before for lesser issues doesn't mean it's appropriate for this issue," Senate Minority Leader Mitch McConnell has said.

Julian Zelizer, a political historian and CNN.com contributor, said the Democratic leadership must be proactive in responding to reconciliation criticism.

"They will have to explain that reconciliation is a legitimate process by pointing to the history," he said in a CNN.com commentary. "They will also have to connect the dots for voters frustrated with the ineffective government by explaining that the constant use of the filibuster has turned the Senate into a supermajority institution where both parties have found it extraordinarily difficult -- virtually impossible -- to pass major legislation."