We are now a week out from the passage of ObamaCare, so it's worth considering what approach the Republican party might take in the months ahead.

The first thing is to understand that, politically speaking, the GOP is in extremely good shape. President Obama succeeded in passing health care legislation -- but he has not succeeded in making it popular. If you analyze the different polls that have come out since the passage of ObamaCare, it shows several things: the president received a slight bump, less than usual for a legislative victory of this magnitude, and it is in the process of evaporating. And because both parties are determined to make the midterm elections a referendum on ObamaCare -- Democrats because they don't want to leave it undefended, Republicans because they believe the public's dislike of this legislation is intense and won't recede -- that is what the elections will largely be about.

Second, Republicans and their allies need to ensure that the president and Democrats now have full ownership of ObamaCare. That means creating benchmarks, such as when we begin to see increases in premiums and taxes, cuts in Medicare Advantage, employers dumping employees into the exchange once it's up and running, an increase in the oversight activity of the IRS (which is responsible for enforcing this new mandate), and more.

The GOP also needs to highlight the negative, radiating effects of ObamaCare, as companies adjust to the new world they inhabit. For example, Caterpillar said ObamaCare would cost the company at least $100 million more in the first year alone. Medical-device maker Medtronic said that new taxes on its products could force it to lay off a thousand workers. The telecom giant Verizon warned that its costs will increase in the short term. As the Wall Street Journal editorialized last week, "Businesses around the country are making the same calculations as Verizon and no doubt sending out similar messages. It's only a small measure of the destruction that will be churned out by the rewrite of health, tax, labor and welfare laws that is ObamaCare, and only the vanguard of much worse to come."

In addition to highlighting the damaging effects of ObamaCare, Republicans need to sear into public consciousness the many false promises and assurances Mr. Obama and Democrats made. Here the stimulus package offers some helpful guidance. In order to pass it, and shortly after he signed it into law, the president and his team made guarantees about how many jobs it would create, including how unemployment would not rise above 8 percent. But a strange thing happened along the way. Unemployment topped 10 percent last year. We have lost rather than gained millions of jobs. The high expectations Obama had created were shattered, and with it the beginning of Obama's credibility. And this, in turn, begins the downward political slide of the Democratic party under Obama.

The same thing can happen, in spades, with health care. Democrats know it, too. Just a few days ago, for example, Senator Claire McCaskill of Missouri said her party has probably oversold the legislation that just became law. "The side on which I'm on, that voted for the bill, probably is overpromising, [has] not been clear enough about the fact that this is going to be an incremental approach over time, [and] the benefits aren't going to be felt by most Americans immediately," McCaskill told MSNBC's Joe Scarborough.

Memo to Ms. McCaskill: It's a little late, Senator. The president has made, repeatedly and on the record, extravagant claims. He promised the moon and the stars. When those things not only don't come to pass, but when people see that their lives are worse off thanks to ObamaCare, there will be a very high political price to pay.

Finally, the GOP needs to connect ObamaCare to the broader narrative it plays into: the modern-Democratic party is fiscally irresponsible to the point of recklessness, it is clueless when it comes to creating economic growth, and Democrats are enchanted with the prospect of centralizing power and control. At a time when trust in the federal government is near an all-time low and disgust with the federal government is near an all-time high, Barack Obama and Democrats have become, as never before, the party of big government.

This is something the GOP can work with.

What will matter, when all is said and done, are the real-world effects of ObamaCare. If it succeeds, then Obama and Democrats will have taken important strides to help them retain their majority status in America. If on the other hand you believe, as I do, that ObamaCare is a pernicious piece of legislation, one that will have terribly damaging consequences as its provisions uncoil, then Democrats will have inflicted on themselves enormous damage.

Both parties have waged everything on this fight. The midterm elections will give us an early indication of which one bet the right way.

Peter Wehner is a senior fellow at the Ethics and Public Policy Center in Washington, D.C. He served in the Bush White House as director of the office of strategic initiatives.