Yes. Have you read up on his rulings?
Reread what I wrote. There's ample modern history of the majority of Democrats voting for a Republican nominee for the Supreme Court. So, clearly there's more going on than just being miffed they lost the election.
If your argument is that Trump's vileness is different, and that the fact the appointment was by him and not by, say, Bush, gives Kavanaugh an uphill climb, that's probably part of what's going on. Trump is the most unpopular president in American history, judging by his average approval ratings, and he's absolutely despised by the large majority of people outside of clusters of conservative power. That means very few Democrats in the Senate will be hurt by being seen as resisting him. Quite the contrary, the real danger lies in losing a primary if one is seen as collaborating with him.
But, I don't think that's the whole story, either. I think that if Trump had picked someone widely respected, like Richard Posner, and the nominee had been forthcoming in response to document requests, the Dems would have decided there were other hills they'd rather fight defending, and would have approved him with relatively little drama.... as they approved a few other widely respected Trump appointees.
For example, consider Jerome Powell. People on the left were disappointed that Trump rejected a highly qualified Fed Chair, Janet Yellen, in favor of putting his own stamp on the Fed. But, they had to admit Powell wasn't an extremist or ideologue, and that he had ample experience and qualifications, and so ultimately he was approved by a vote of 84-13 (with some of the Nays coming from Republicans, like Ted Cruz and Rand Paul). So, we know for a fact that Democrats don't just automatically oppose anyone Trump nominates to a key position. When he picks someone good, most Democrats will vote to confirm. When, on the other hand, he picks an extremist, they resist.
Now, I'm curious, did you not know that?