As the Supreme Court heard oral arguments over a fundamental challenge to the Affordable Care Act--Obamacare, for many--the only thing clear is that the vote is likely to be tight. Chief Justice John Roberts, who was a crucial swing vote saving the legislation from a challenge three years ago, didn't ask any questions that seemed to illuminate his position.

The challenge is whether the law permits tax subsidies critical to coverage for millions to be offered through federal-run insurance exchanges, rather than ones run by individual states. Should the court find in favor of the challenge, the law would effectively be gutted. So many would be unable to purchase insurance on their own that the balance between the number of enrolled and policy prices would be upended. Rates would shoot up, many would lose coverage, and Congress would likely have to consider either changing the law--unlikely with Republican control--or ending it to keep the unenrolled from facing inevitable financial penalties.

Many in the business community would be happy to see an end to the law. But it's a shortsighted and ultimately foolish position. A loss of the ACA would be a giant step backward hurting businesses large and small in all sorts of ways.

To make medical care unaffordable for millions would mean legions of workers would be more likely to be ill, with a two-pronged attack on companies. Sick workers either miss work, which lowers productivity, or show up for work because they can't afford not to and make others sick, having an even greater impact on productivity. Workers are also consumers. They're part of the largest segment of the country's economic engine. When they're sick, they lose time and pay. Lower income means less money to spend, which slows the economy, keeps a recovery tepid, and again hurts businesses.

In addition, as the job market heats up, small companies could increasingly find themselves in competition with middle market and large ones. The availability of healthcare coverage is an important part of attracting and retaining employees. The ACA can help startups and young firms compete on more equal grounds even if they don't have the large employee populations that lend themselves to better negotiated pricing.

Is the Affordable Care Act perfect? Certainly not. Few pieces of lawmaking even seem to approach decent. The administration misrepresented a number of aspects early on, like the promise that people could keep their current plans if they liked them, suggesting a grandfathering clause. The legislation is predicated on keeping the existing health insurance infrastructure and players snug and happy rather than trying to construct an approach to healthcare that was practical and not leaping ahead in cost faster than almost anything else in the country, except perhaps the price of a college education.

But often you must deal with what exists and not plan some grand and glorious structure that hasn't a hope of gaining the support necessary for existence. If the ACA goes down, there isn't an alternative that will take its place. Republicans are talking about a plan that's similar to one previously proposed. But there is no way it could pass to close up a gap, and it's questionable as to whether some of the assumptions, like capping potential malpractice suit awards would help contain costs, even hold water. (Some analyses suggest that total malpractice costs are under 3 percent of all healthcare spending. The savings have to be found elsewhere.) More importantly, there is no draft of legislation that could possibly get enough support in the House and Senate to overcome a likely presidential veto.

A loss of the ACA will leave nothing to replace it and the end result will be pain not just for those who lose their healthcare, but for small businesses and entrepreneurs as well.