Said Josh Holmes, Mitch McConnell’s former chief of staff, quoted in a NYT article floating the theory that the GOP plan not to act on an Obama nominee to replace Scalia "could alienate moderate voters and imperil incumbent Republicans in swing states."
I think Holmes's assessment is correct, especially coming after years of Obama's pushing the limits of executive power (one of the issues in a pending Supreme Court case right now). Why wouldn't the Senate make its vigorous claim to power and exert it? That, to my mind, fits the most fundamental idea about separation of powers, expressed in Federalist 51:
But the great security against a gradual concentration of the several powers in the same department, consists in giving to those who administer each department, the necessary constitutional means, and personal motives, to resist encroachments of the others. The provision for defence must in this, as in all other cases, be made commensurate to the danger of attack. Ambition must be made to counteract ambition. The interest of the man must be connected with the constitutional rights of the place. It may be a reflection on human nature, that such devices should be necessary to controul the abuses of government.ADDED: It was a creed written into the founding documents that declared the destiny of a nation: Yes, we can.