Obama took...actions that set extremely dangerous precedents...he waged a war of choice in Libya without permission from Congress.There is no universe in which this works as an Obama precedent. The military actions that presidents have authorized without Congressional approval have numbered, historically, in the triple digits. Which ones count as "wars" and "wars of choice" will depend on who you ask, but Friedersdorf has a hilariously steep hill to climb if he's going to exclude all of them, while singling out Libya as the camel's nose in the tent. There's an extensive history of critics alleging precisely this point of unconstitutionality against presidents, and if Friedersdorf is unacquainted with this it can only be because he's completely unacquainted with the anti-war left.
None of this absolves Obama, of course, from any kind of moral judgment. But as a simple matter of practical assessment, it does lay down a marker of what we can expect from a modern American president. To support Obama and approve of the job he is doing is not to endorse him as an ideal - it is to compare him to the alternatives on offer. Not in Imaginationland, but in the grim reality of 21st century American politics.
This perspective is worth consulting when critics like Friersdorf characterize Obama's defenders on the left as blinkered Pollyannas failing "to see it all with open eyes". It's precisely because we see history - all of it - that we judge Obama accordingly. When demagogues like Rand Paul float visions of world peace before us, and ask us to judge the sitting president by that standard, we think back just six years ago when another Senator said the same things. We remember.