The issue of research into embryonic stem cells tends to generate a lot of media attention, and it's easy to see why. Some believe that such research has almost miraculous potential to cure many ailments. Others feel that destroying a human embryo for study is extinguishing a human life. The debate combines science, politics, and ethics, and the end result is white-hot controversy. But when it comes to investing, it's best to view the subject with as much detachment as possible.

Recent events are again raising the profile of embryonic stem cell research. The House of Representatives has passed a bill that would eliminate restrictions on federal funding of the studies. Now, the Senate is gearing up to debate the legislation. The proposed change comes as new polling shows that a significant percentage of Americans favor embryonic stem cell research -- 58% in a recent CBS News poll.

No matter how the legislation fares, though, it's important to note that very little is likely to change, at least in the near term, for companies that specialize in the area, like Geron (NASDAQ:GERN) or ACT Holdings. Sure, federal support may increase the chances that embryonic stem cells will yield novel treatments. But the path to success is still likely to be peppered with setbacks and failures over a period of years and at a cost of millions, if not billions, of dollars. Federal investment is not a magic wand that will produce cures overnight.

Further, even if national legislation does fail, as seems likely, public investment in embryonic stem cell research will increase substantially anyway. California voters approved a referendum that will allocate $3 billion in state funding over 10 years to the field, and New Jersey is considering spending hundreds of millions on stem cell research and a research center at Rutgers University.

Despite the promise suggested by early studies, embryonic stem cell research remains highly speculative. More concrete results, not the amount of cash being poured into research, are the best basis for investing decisions.

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Fool contributor Brian Gorman is a freelance writer in Chicago. He does not own shares of any companies mentioned in this article.