Doesn’t that bring us full-circle back to the Line Item Veto (which was already declared to be unconstitutional by SCOTUS?)
The Democrats imagined at the time that they should have FULL FUNDING so they automatically opposed any effort for sequestration. Through their control of Congress they finally passed a law prohibiting the President from doing it on his own, and then they allowed outside groups to take the whole issue to court.
Congress appears to have the Constitutional power to control sequestration with or without the President, and they can also allow the President to 'jus do it'.
The Democrats are giving up on this one too easily ~ but I can hear Teddy Kennedy rolling over in his grave ~ the line item veto you mentioned was supposed to be a way back to Presidential sequestration power ~ but the court said 'yo'all cain't do it that way neither'.
It's a parallel but I can see them massaging the nuances to avoid it.