Judge Brett Kavanaugh has disqualified himself from consideration from a seat on the Supreme Court by two things: his past statements about presidential immunity from civil and criminal prosecutions while in office, and questioning the efficacy of U.S. v Nixon, the unanimous Supreme Court decision that ensured the release of the Watergate tapes which ultimately led to President Nixon's resignation.
Our founders did not create a legal frame work where our president is above the law. While there was discussion of making George Washington a king, having fought a revolutionary war against the tyranny of King George III, Washington found it abhorrent that he should become the next King George. We should not now confirm a Justice to the Supreme Court who would have the power to resurrect that idea.
President Trump is under investigation for: obstruction of justice and collusion with Russians; he is facing civil lawsuits over business matters involving gifts or payments from foreign and domestic governments, defamation, misuse of his family charity for personal business, and hush money paid to sexual partners prior to the 2016 election. All of these things will predictably play out, perhaps creating a criminal indictment, during Trump's presidency.