Sure, and they should vote in a way that honors that. Don't you feel that obstructing seems different, though, than simply honoring their mandate? It is as if the obstructionist is speaking for more than their electorate, for people that did not vote for them. And that would be true for either side obstructing.
Just because previous congresses haven't chosen to simply not hear a nomination doesn't mean it isn't within their charter or right to use it.
Every congress and every president (and every supreme court) have tested the limits of their powers. If they did not have the right to deny a hearing or a vote, then I suppose that will be tested against the constitution by the next president who takes congress to the supreme court and forces them to act. I suppose the supreme court would act in its self interest, though, and force congress to act.
I don't know, but that's why we have three branches who are always testing the limits of the powers granted them via the constitution.
Actually, we have google. Let's find out. "Can Obama invoke the Writ of Mandamus against US Congress"
The answer is no. From one of the many sites:
Can Obama invoke the Writ of Mandamus against US Congress if they refuse to consider his Supreme Court nomination of Merrick Garland?
No, he cannot.
The Senate may not be compelled to perform any action, including taking up the pending nomination. Strictly speaking, the President has performed his Constitutional duty by nominating a judge. The Senate may decide to serve coffee on the floor instead of considering the nomination, and they're still entirely within their authority.
Moreover, since neither Judge Garland nor President Obama have a right to specific Senate action, no writ of mandamus could be issued, nor could such a writ have any legal force given separation of powers concerns. Such writs are issued in order to compel an action required by statutory duty, but the Senate sets its own rules.
At some point, President Obama's supporters are going to have to accept that the Senate may not be compelled to consider his nominee. As the President himself has observed, "elections have consequences," and Democrats will have to win more Senate seats in order to control that chamber's agenda.
So there's the rub. The senate can continue to refuse. There's two ways to accomplish this:
1) present a supreme court candidate that will pass the senate. Perhaps if they chose someone in the vein of Scalia, the senate wouldn't be so hesitant.
2) the electorate needs to change the senate enough that the president's choices will be chosen.
That's it. The senate can block indefinitely, and the people will have to live with an 8 seat court for as long as the senate chooses to do so.
You may disagree that the senate should use this power in this manner, but it's in the constitution. Go ahead and change it if it's causing problems, or change the senate, or change the nomination.