There are some that dabble in a limited fashion. e.g. D-Wave, which has attracted the business of companies like google.

However, private companies typically do not engage in long-term research that isn't likely to lead to directly commercializable results. I know this flies in the face of red-blooded 'merican "all socialism is evil" doctrine, but public sector research, funded by tax-payer money, is needed to build the foundations for tomorrow's industries. Quantum computing, like many other bleeding edge fields, is too immature, too high-risk, and with pay-offs that are far too distant for the private sector.

Research and education are both investments that can yield fantastic returns, but they are long-term investments and require steady commitment rather than periodic outbursts of zeal punctuating long periods of apathy. A minor cut now might help balance the books today, but the lost opportunities down the road will more than negate that.

Top researchers don't hang around after you cut the funding they run their labs and pay their students and post-docs with. They go where the money they need to work is, and if they can't find that in the U.S., they'll likely find it in Canada, China, Australia, etc.. The U.S. is far from the only country doing quality research in QC these days.

Yeah, but the problem is that you pretty much have to cut social security and the military, which are two things that can't be cut without unless you end your political career.

So what is left to do is to scramble for the peanuts, while trying to appear economically "though".

There are at least some bigger peanuts than trying to take a few nibbles out of the NSF budget ($7 billion) though. Like farm subsidies (~$20 billion), homeland security (~$45 b), or department of justice ($27 b). But I suppose I'm not surprised they didn't take on any of those, either.

All of which a lot of lobbyism is paid to protect.

Patents only last 17-20 years. Anything with a longer development timeline to profitability, which quantum computing surely has, cannot be accomplished by the private sector. Either you have to fund the research with public money, or you have to modify the patent system.