That sort of “shame the Republicans into accepting a moderate conservative” strategy relies upon the Republicans demonstrating rational behaviour.
What about the past eight years led you to think that was a good bet?
What is the strategy if Obama nominates a centre-right judge but the Republicans still block him? Do you think that rational appeals to constitutional tradition will sway Trump and Cruz voters during an election year?
Keep in mind that the bulk of the Republican House is so heavily gerrymandered that they view their only electoral threats as coming from the right.
You end up fighting just as hard for a pre-compromised outcome. See: Obamacare, etc etc etc
