It seems the president doesn't even know what Bitcoin is, how can the US Dollar back Bitcoin which is a decentralized currency. Their is no meaning in all these, it is just a mere talk trying to gain people's interest and I'm not surprised because this is the nature of politicians. No needs for the president to talk too much, the only impact he can offer to bitcoin is mass adoption of bitcoin if truly he has bitcoin in mind.
One thing I know is that bitcoin will always grow even without Donald trump, bitcoin has gone through difficult times but still it still remains what it is. Donald trump can't make bitcoin better because bitcoin is not fiat or a centralized currency. Trump understands that bitcoin has gained so much users, I think he just trying to get favour from bitcoin users.
I would say that bitcoin is irrelevant to politics. Well, simply because while it would be good or bad depending on what the president does with bitcoin, we have seen the all time high during Biden, and yet a lot of people think that Biden hates bitcoin, or at the very least Biden's team hates bitcoin because not like Biden knows what bitcoin even is, he probably doesn't even know about it.
So all in all, if bitcoin thrived under an administration that people think hates bitcoin, then I would say it really doesn't matter. One thing that would be terrible is if any of them would ban it, and neither is banning it, that is not on the cards, so it really doesn't mean that any of them will make a big difference, it is going to be same in either case.