It’s now crunch time for President Obama’s health care bill.

Given the unpopularity of the overall health plan (individual components of the bill are popular, but the entire package is not), one might think that Mr. Obama and the Democratic Congressional leadership would move to areas viewed as more important by most voters (the economy and jobs, for example). This would be especially true in the wake of the Scott Brown upset victory in Massachusetts, which deprived Democrats of their filibuster proof majority in the Senate.

Nevertheless, the bill has gained new life by the Democrats’ willingness to use the controversial “reconciliation” procedure in the Senate, which allows budgetary bills approved in the other House to be approved in the Senate by a simple majority vote of 51 senators. Democrats currently hold 59 seats and Vice President Biden would be allowed to break any 50-50 ties.

Wisely or not, the Democrats are willing to soldier on, both as a matter of ideology and practical politics. Many liberal Democrats believe that the current political environment, with a Democratic president and large party majorities in both houses of Congress, is the best one that they are likely to see for many years, and that an all out drive for passage is essential. More pragmatically, many Democrats also believe that Mr. Obama’s inability to pass this legislation will greatly damage his presidency and will also mark Congress as ineffective.

Because of arcane procedural rules, former Bush advisor Keith Hennessy states that the most feasible path to passage of the health bill is likely passage of the previously approved Senate bill by the House, then passage by the House of a modified version of the bill previously approved by both houses, and then passage by the Senate of the modified House bill. President Obama would presumably hold the first bill aside, even though it has been approved by both houses, and then sign the second bill after it is passed.

The biggest hurdle here is that the House initially would have to pass the Senate bill without firm assurances that the bill will be modified. There is much in the Senate bill that is very susceptible to attack - special treatment for states (the so-called Cornhusker Kickback and Louisiana Purchase) and, in the view of prolife members, a loophole that would allow federal funding of abortions. If the Senate fails to act on a modified bill, President Obama might well decide to sign the enacted legislation as is (or allow it to become law without his signature), with House members taking the considerable political hit for the controversial provisions.

Abortion is a particular sticking point, since at this writing Rep. Bart Stupak, a Michigan Democrat whose antiabortion amendment was included in the House bill (but not the Senate’s), has refused to sign onto the language in the Senate bill and states that he has 12 House members, each of who voted for the previous bill, who agree with him. (He also says, however, that it may be possible to work out language.)

The House bill initially passed just 220-215, with 39 Democrats against. Speaker Nancy Pelosi is working with very thin margins, especially with many Democrats, over 80 of whom come from districts voting Republican for president in 2004 or 2008, extremely skittish about the bill. It is clear Ms. Pelosi currently lacks the votes today to prevail. (A House Democrat estimates she has 201 votes currently.) Whether she and President Obama can find them in a difficult environment very much remains to be seen.