The President and only the president can nominate a supreme court justice, and the Senate and only the Senate can, if it wants to, confirm that nomination.
The President is not required to nominate someone merely to satisfy any body of Senators, and the Senators are not required to vote on or approve anyone the President nominates.
Nothing opposed by the Constitution has yet taken place with any Supreme Court nomination, at any time whether during Obama’s time or Trump’s.
The Dims are using the sheeple’s Constitutional ignorance to displace the Constitutional demands of Supreme Court nominations with the Dims’ mere political demands.
That is a very clear explanation.