As any lawyer knows, the difference between "and" and "or" can mean winning a seven-figure award versus having your a case tossed out of court. Or, in this case, millions of dollars for stem cell research versus none at all. It all started last week, when the Republican Platform Committee approved an amendment to the party platform regarding embryonic stem cell research. The change boiled down to that one crucial word—from "and" to "or"—in the platform's call for the ban of (emphasis added): "the creation of or experimentation on human embryos for research purposes." Which means, essentially, is that if the party has its way, virtually all human embryo research, from freezing embryos at fertilization clinics to the privately-financed creation of new stem-cell lines, will be shut down. Granted, McCain is not obligated to follow the party platform—and (thank God) he's shown a willingness to flip his party the proverbial bird in the past. Both the GOP candidate and the GOP itself have publicly opposed the creation of embryos for research purposes, but they differ substantially on the rest: McCain supports work with embryonic stem cells, while the party bigwigs want to stick to sources like umbilical cord blood and iPS cells. The good news is that, even if McCain is elected, a full ban on embryo research would never make it through what will almost assuredly be a Democrat-heavy House and Senate. But it's also doubtful that a McCain presidency would do much to get those investment dollars flowing to research labs. What does Obama think about stem cells? You can find out for yourself here.