Does Cap and Trade beat carbon tax for reducing emissions?

Of course, they're theoretically identical.
The carbon tax is much simpler to administer, though, and less vulnerable to corruption. (See the most recent cap-and-trade bill -- it was a porky monstrosity.) However, it's less politically feasible than cap-and-trade. So some would say we should do what we can, however imperfect. I don't think so.

Myself, I think we haven't done the homework on climate change yet, and we don't know if aggressive carbon pricing is good for the US or the world in cost-benefit terms. A less-than-ideal pricing scheme, which is what we'd probably get -- not aggressive enough, too soft on industry -- would be a waste of money with negligible effect on emissions. I really wouldn't touch it.

If we have public money to spend on climate change, we should spend it on clean energy R&D, and infrastructure and humanitarian aid to cope with the effects of climate change. We don't have the political will to drastically reduce consumption in the US; we don't have the power to make other countries drastically reduce consumption; and we don't have enough evidence to believe that such aggressive efforts are a net economic gain.

The principal of figuring out how much pollution the earth can handle, and issuing tradeable licenses to pollute up to that amount, is sound. This beats a carbon tax, which imposes the same linear cost of pollution past the point the earth can no longer absorb it, while a market system will raise the price asymptotically as the resource of allowable pollution becomes scarce, so that a balance must be found. I have issues, however, with the government arbitrarily deciding who gets the licenses initially. I would prefer to split them amongst the earth's entire human population, allow those who pollute less end up being compensated by those who pollute more, and therefor have to buy the licenses.