We are about to hear some major league caterwauling from the democratic party but they don't really have a ethical leg to stand on. The final YEARS (not 11 months) of Bush's administration saw Harry Reid of the Senate block the votes, if they got a vote, of hundreds of Bush nominees for federal and appeal judgeships. The press never questioned if Harry Reid was right or wrong but the flood gates did open after Obama got into the White House. So there is precedent for the Senate to block judgeship votes.
It is also constitutional. The beauty of having three branches of government (and a bicameral legislative branch) was that if one branch got too radical the other two branches could drag that branch back into the moderate zone. If a president nominees a card carrying communist, black panther, or someother GLTB activist then it is the responsibility for the Senate to stop such a vote in it's tracks. Even a less radical nominee, if outside the mainstream, should be given very careful consideration. Justices like Scalia were conservative but unlike so many liberals (Ginsberg, Sotomayor, and Kagan) give respect to the US Constitution which should be the standard.