Given that the Court can operate just fine with eight justices and given the fact that Appeals Court Chief Judge Garland is a Clinton-appointed center-left judge who will very likely vote with the liberal wing of the court (Sotomayor, Breyer, Ginsburg, Kagan) in nearly every case, why should Republicans rush to confirm him to the seat held by the late Justice Scalia? The Constitution merely says that the President shall make appointments "by and with the advice and consent of the Senate." The Constitution nowhere obligates the Senate to act. The Senate is not legally obligated to do anything with the President's nominees.
I see no compelling reason to hold hearings on Garland other than "elections have consequences and Obama was re-elected in 2012." Yet, the Senate was duly elected, too, and a third of its members were elected or re-elected more recently in 2014. In fact, Republicans gained seats in the 2014 election. So technically, if there is any so-called "election mandate" it leans toward the Republican Senate and away from Barack Obama.
I do not deny that Merrick Garland is a fine man personally, probably well-qualified, and likely decides most uncontroversial cases fairly and impartially. But the most controversial and politically divisive issues are precisely those issues that reach the Supreme Court. The mainstream media tells us that Judge Garland is a "centrist, consensus pick" but examination of his judicial record does not bear that out. Conservatives should not acquiesce to the President on the Garland nomination - this is the most important Supreme Court nomination in decades - confirmation of Judge Garland would mean a liberal 5-4, possibly 6-3 majority (counting Justice Kennedy who often votes Left) for many years to come.
While I am not necessarily opposed on principle to giving Judge Garland a hearing or an up-or-down vote, a Supreme Court nomination is inherently a political animal precisely because of the "advice and consent" clause. The longer the political process plays out without a clear unequivocal statement by Republicans saying "absolutely not, we will not confirm him," the more Mr. Garland will be seen as "legitimate" by the Left, the media, et al. and pressure will mount against Republicans to confirm him. Republican Senators should state unequivocally that they not confirm any new justices until after the new president is elected.
If Hillary Clinton is elected, I would be happy to confirm Merrick Garland in a lame duck session of the Senate. Judge Garland is probably better (i.e. somewhat more judicially conservative) than any progressive, left-wing judge Hillary would appoint. Remember how we were told that that Ruth Bader Ginsburg and David Souter were "moderate consensus picks." The rest of course, is history.