Congress, be bold on Obamacare. It's what you're there for.

The moment the Congressional Budget Office released its score of the Obamacare repeal bill passed recently by the house, hysterical partisan voices began their hue and cry. Under this baneful new reform, headlines wailed, "23 million would lose health coverage."

That isn't actually what the nonpartisan CBO's report said. But politicians and activists know a powerful rhetorical point when they see it. And there's great danger when such a potent point can be made that all resolve to do something necessary will collapse into a puddle of political cowardice.

Lawmakers should not allow alarmism to distract their attention. Obamacare is shredding the individual insurance market, as the flight of insurers from its exchanges illustrates. Just as Republican members of Congress are likely to take a hit politically for whatever they end up passing, so they are certain to take the blame and a bigger hit if they timidly back away and allow this appalling law to keep crippling the nation's healthcare system.

CBO does not have a crystal ball. Its estimates on Obamacare have a poor record. The CBO did not foresee the 105 percent average increase in premiums since the law went into effect. In 2013, CBO overestimated, by a staggering 16 million, the number of people who would sign up for Obamacare exchange plans by 2017. Its margin of error was much bigger than the total 10 million who have enrolled. Even their prediction from last March was off by 5 million, or 50 percent.

CBO also dramatically underestimated the costs of Obamacare's Medicaid expansion. It projected that insurers in the exchanges would make huge excess profits, creating an $8 billion surplus for Obamacare's "risk corridor" program. In fact, the program ran a deficit of nearly $8.3 billion in just its first two years as most big insurers suffered massive losses. These continue and are driving insurers out of the market.