I remember discussing Bush, Cheney, Rumsfeld, the open ended War on Terror and the implications for civil liberties, the invasion of Iraq and all the political upheaval that happened around that time a lot throughout that administration. I still have email threads of conversations I had while at work, before I had you lot to talk shit to (as we grew up and my friends started, you know, actually working rather than talking bollocks all day.) If I had been a member here at that time I would have been a pretty regular poster in the threads about US politics and the War on Terror. It was the period I became really politicised to the extent I am today and it's interesting to consider how I might be different if none of that had ever happened.
So I think the answer is it depends what he does. If he does a lot of controversial stuff he'll stay in the public consciousness big time, and it will probably politicise a lot of younger people who might not otherwise have thought about such things. Whether any of that will or could be channeled in any kind of useful way to bring about change is another matter, it might only exacerbate the existing feeling of impotence that is translating - along with other things - the lack of trust and the toxic political environment today. But if he is even more egregious in pursuing policies that favour the rich and hang the poor out to dry, as looks to be the case with nominations like DeVos, that could easily push people to taking action. You can only hope.
Of course if he turns out to be a lot better than people expected he will get some credit for that, there will be some sheepish people on the left, some who will continue to criticise him, some who praise him... and then itll all die down in all probability and people wont think about it as much. Such is the way of the world, bad news is a lot more interesting than good news, usually. Though if he does really good things, if he gets America growing at 5% or 6% or 8% again (not going to happen), if the rapid shrinking of the state actually yields results, and education gets better for having money sucked out of public schools, and he replaces ACA with something better that still covers the poor, and he defeats ISIS, then for sure he will be remembered extremely fondly, the more so for proving everyone wrong and overcoming adversity.
No President be it Obama or Trump deserve any credit or will deserve credit for the inevitable destruction of ISIS.