Because the federal government operates insurance exchanges in 36 states, the ruling—which the Obama administration will almost certainly appeal—places much of the Obamacare regime into question. Conservatives argued repeatedly that the law only allowed for federal subsidies in “an Exchange established by the state.” Supporters of the legislation, while conceding that the law was poorly and hastily drafted, argued that Congress intended to extend subsidies to individuals in both federally-run and state-run exchanges, and that the IRS exercised appropriate discretion in tailoring the rule to meet that intent. Today the Appeals Court clearly disagreed.

The ruling provides yet more evidence of the problems inherent in legislating on such a massive scale, which I noted earlier this morning. Even under the most favorable interpretation taken by the law’s supporters, Congress rushed to pass a sloppily worded document, leaving it to unelected bureaucrats to decipher lawmakers’ true intent. The plaintiffs—and the court in its ruling—believe that the administration clearly overstepped its authority, a fact that will no doubt energize those concerned about the executive exceeding its power. Regardless, either interpretation makes a compelling against future attempts to enact major policy changes on such a broad scale in such a fast manner.

This post was originally published at the Wall Street Journal Think Tank blog.