This is day 216 of the U.S. Senate refusing to hold hearings on the confirmation of Merrick Garland to the Supreme Court.
On day 215, as widely reported, Sen. John McCain said, "I promise you that we will be united against any Supreme Court nominee that Hillary Clinton, if she were president, would put up." Although his spokesperson walked back that line, McCain is stating the obvious. In this heads we win, tails you lose world, Republicans in the Congress hold all the cards and are more than willing to continue to act in bad faith to stretch the process beyond its limits. Three elderly justices could resign or die in the next president's term, but there is no requirement for the Senate to confirm or hold hearings on any nomination put forward by the president. Under our system, which includes the 60 vote supermajority in the Senate to accomplish anything, there is no legal recourse if the Senate refuses to hold hearings on the Supreme Court nominees. In fact, the Senate could refuse to meet. The Supreme Court has ruled that the Senate can be considered to be in session even when they are not meeting.
As previously noted, the Senate Majority Leader could send the president a short list of acceptable Supreme Court nominees - as short as one person- effectively being the person who actually nominates the justice, instead of the other way around.