I think it's a perversion of the "advice and consent" language from the Constitution for the Senate to simply stonewall a nomination process until they get the President they want.
I was just thinking today about why Canada's Supreme Court isn't remotely politicized in the same way as the US. Part of it may be that we're just not as partisan, but I think the main thing is that with our parliamentary system, if the party in power has a majority—which they do the majority of the time—they can basically pass what laws they want. Of course, they generally refrain from doing deeply unpopular things since they'll pay for it at the next election, although even that does happen: eg. the Mulroney (conservative!) government implementing a 7% goods and services tax. Probably played a large part of them being out of power for a decade+ immediately following, but was great for the country fiscally from there forward.
Anyway, since the government can largely do what they want, there's much less need or reason to essentially try to enact 'legislation from the bench'. I couldn't even tell you the political leanings of our SC justices.
There are still plenty of downsides to this system of course (lack of proportional representation comes to mind), but it does appear to be more functional in a lot of ways than the US. And probably not by accident—the Canadian system was developed almost a hundred years after the US, and had it and other more recent governments as models; it was also soon after the US Civil War, which played a part in Canada adopting a strong federal system with less provincial power, relatively speaking.
Of course, it's easy to say all that. Much harder to actually enact significant reform!
Why would you need to block a vote you know you will win?
With a Democratic majority, Garland would have been confirmed. It's exactly because no Democratic majority in the Senate existed that Garland wasn't even voted on (and actually didn't even get a hearing).
That's hardly the whole truth. McConnell refused to even hold hearings.
"Elections have consequences" and all that.
Note: 15 nominations were not voted on by the Senate, including Merrick Garland.
https://en.wikipedia.org/wiki/Unsuccessful_nominations_to_th...
Part of that procedure is having your party in charge of the Senate at the time of said nomination. Obama did nominate someone, he simply could not get him confirmed. That's on Obama (and Democrats more generally).
Trump will also nominate someone, and because his party has a majority in the Senate, that nominee will likely be confirmed whether Trump wins the upcoming election or not.
I am 100% certain that if Obama had a Democratic Senate majority when he nominated Merrick Garland, his nominee also would have been confirmed. (As a registered Democrat myself, I would have demanded it.)
There is no other precedent here: you accomplish in office what you can (procedurally) accomplish. Trump lucked out here; Obama didn't.