One of the common points I've seen in the wake of President Trump's decision to pull out of the Iran deal is to argue that if President Obama had handled it the right way, then President Trump wouldn't have been able to get us out of it as easily as he did.
Which, frankly, is true enough. The JCPOA was never ratified by the Senate, so it's not a formal treaty, and what one president does by executive order can be cleared out just as easily.
However, I put somewhat less stock by the argument that this obviously means President Obama should have governed more to the center on this and many other things. To be blunt, most of the people I see using that argument are the same ones that argue that President Trump was fairly elected and that the Democrats in Congress need to stop taking advantage of their numbers to throw up roadblocks. If that were true, it would have applied equally well to the Republicans in Congress under President Obama, yet very few conservatives seem interested in acknowledging that.
In reality, there's a balance between the two. A president whose popular support has grown thin enough that they have to deal with a slight majority or minority for their party in Congress should be changing what they support and who they nominate in order to acknowledge that shift in public opinion. Blaming Congress alone for throwing up roadblocks (as with some of President Obama's efforts or with some of President Trump's nominations) isn't quite fair, since the system was set up to give them that power and to force the president to deal with that limit.
At the same time, Congress can't ignore the power the president holds. The best they can do is to make nothing useful happen if the president is pushing for a law or a nomination that most of them don't approve of. Sometimes that's warranted, but much of the time it doesn't actually serve the people's best interest to do that.
Unfortunately, fairly and consistently figuring out where the balance between those powers lies is rather difficult as long as we're all inclined to give our own side more of the benefit of the doubt.