I believe that there should be some real skepticism of a single accusation of this sort; that being said, the actions since this issue emerged have shown Ford to be far more credible than Kavanaugh. Republicans accuse Democrats of politics (there's politics on both sides, of course) because their position is unsupportable on the facts.
Democrats did not use this sort of tactic against Gorsuch (who arguably was being appointed to a stolen Supreme Court seat). Ford even made her contact with her Representative before Kavanaugh was nominated with the full understanding that an equally extreme conservative Republican would be appointed instead - but it would be an extreme conservative Republican who had not committed sexual assault. Ford took a lie detector test with an independent retired FBI investigator that validated her assertion that she is certain that he committed this crime.
Ford answered every question asked of her; look at this graphic of just how many questions Kavanaugh refused to answer while testifying (
https://www.vox.com/policy-and-politics/2018/9/28/17914308/kavanaugh-ford-question-dodge-hearing-chart).
Republicans fought an FBI investigation; when they heard of additional accusations they tried to accelerate the approval (with no explanation as to why 71 days was a magical time; this next appointee will probably be serving until the year 2053 and yet there was a rush in days
Even now, there are reports that the White House is setting limits on what the FBI can investigate. I believe that there actually should be limits - but can you identify any situation in which Republicans would have trusted the Clinton or Obama Administrations to be the ones setting limits on what the FBI could investigate? Why does the Trump Administration get special privileges?
And I think that refusing to investigate Mark Judge, who is an eye witness named by the accuser (who, I will remind you, passed a lie detector test), is undefendable.
Finally, Kavanaugh himself has ruled as a judge that employers can use lie detector tests in the hiring process (which is one of a vast range of things that cause many liberals to be concerned with him). If he truly believes that is valid for situations where employees are being hired for jobs with vastly less power than Supreme Court Justice, and jobs without a lifetime hiring guarantee, should he be willing to take a lie detector test himself?