Currently the Republican held senate has vowed to block any supreme court nominee by President Obama. The president recently nominated Merrick Garland. Merrick is fairly moderate and, while he's no Scalia, he's probably preferable (in Republican eyes) to anyone Sanders or Clinton would nominate with a Democrat controlled senate. If the Republicans block the nomination until November and then see a Democratic victory, is there any mechanism to stop the Republican held senate from cynically confirming Garland as a lesser evil?
Note: I'm not asking about whether such events are likely to transpire. I'm just wondering if there is a constitutional or senate rules mechanism for the president to keep the senate from waiting and then confirming his nominee.