Obama certainly did his part in strengthening executive power and your attention to the role that Democrats played in this is well deserved. This whataboutism, however, does not absolve the Republicans who are pushing the Unitary Executive theory -- of which a monarchy is the ultimate expression. Therefore, the name "no kings" -- a catchy title that captures the undeniable thrust of the founding of the USA and warns of the end of the slope our country is accelerating down.
https://en.wikipedia.org/wiki/Unitary_executive_theory