A bad CBO score would likely mean that Trumpcare adds to the budget deficit instead of decreasing it as promised.
From the op-ed:
“In the coming days, the Congressional Budget Office will release an updated analysis of the Senate bill to repeal and replace Obamacare. The CBO will likely predict lower health insurance coverage rates if the bill becomes law. The American people and Congress should give this prediction little weight in assessing the bill’s merit. The reason: The CBO’s methodology, which favors mandates over choice and competition, is fundamentally flawed. As a result, its past predictions regarding health-care legislation have not borne much resemblance to reality. Its prediction about the Senate bill is unlikely to fare much better.”