If the Democrats use budget reconciliation to bypass the Republicans, they will be making a big mistake.

Reconciliation is not meant to handle these sorts of problems; it’s meant to help Congress get revenues in line with outlays without letting protracted negotiations push us into a budget crisis. It’s not possible to do any sort of comprehensive, rational overhaul of the Senate health bill — which after all, was intended to be the opening salvo in a negotiation, not the final bill.

More broadly, for all that Democrats are declaring that they have a mandate, it’s pretty clear that the public does not want them to pass any of the health care bills on the table — which has to include the Obama plan, since it is only a minor tweak on the existing proposals. Polls have shown more Americans opposing passage than supporting it since early summer, and opposition has risen fairly steadily over time.

While President Obama promised health care reform during the election, the plan he ran on was much different than the one he is hoping to sign into law. Most notably, it contains an individual mandate, which he opposed during his campaign — and which the American public opposes. The individual mandate, along with the hefty price tag, are the two factors that Americans who oppose the legislation are most worried about.

Of course, sometimes politicians have to do the right thing rather than the popular thing. But this cannot be a blanket authority to ignore the desires of one’s constituents.

Democrats have had plenty of time to make their case. They have failed to do so. The longer they have talked, the more firmly the voters have rejected their ideas. If Congress goes ahead anyway, they will pay a terrible political price.

Many progressives are pushing the notion that having already once voted for it, Democrats will pay that political price no matter what, so they might as well pass it. That ignores several factors. First, a hated bill that failed last December is not going to engender the same ire as a hated bill that passed in May.

Second, Republicans will capitalize on the use of the reconcilation process, characterizing it as a procedural trick. And third, the provisions that go into effect early, like forbidding insurers to discriminate on the basis of pre-existing conditions, are probably going to push up the cost of coverage in the short run.

It’s far from clear that Democrats have the votes to pass anything close to this bill, even through reconciliation. Pro-life Democrats in the House may not go along with the Senate bill, which has more liberal language on abortion.

But even if they eventually go along, Speaker Pelosi could still be short of the votes she needs, thanks to attrition. To pass the Senate bill, she will probably need to flip a significant number of “no” voters into the “yes” column. Since most of the “no” voters come from relatively conservative districts, this is tantamount to asking them to commit political suicide.

Read more opinions on the New York Times' Room for Debate blog.