Alleged accusations are worthless.
Conservatives thought such allegations had great value for a couple decades, when they relied on them to label Clinton a groper, harasser, rapist, etc. Now they're reconsidering, when the same thinking is used against one of their own.
There was proof of what Clinton did in at least one case
There was never any proof that Clinton engaged in any predatory sexual behavior. What there was were mostly rumors -- claims that weren't even supported by sworn testimony, much less hard evidence. In the case of Jones, there was sworn testimony, but nothing else, and the testimony was undermined by her attempt to bolster it by identifying unusual characteristics of Clinton's genitals -- characteristics that ended up not being true. The other major claim against him was the Broaddrick rape rumor, but Broaddrick herself swore under oath that it was false, so there's nothing there.
In Trump's case, nothing has been proven, but several of the claims are stronger than the he-said/she-said hearsay accusations against Clinton.
(1) The child rape allegation is supported by two separate pieces of sworn testimony -- the testimony of the alleged victim, and corroborating testimony by an alleged witness.
(2) The testimony that he raped his wife is, likewise, supported by sworn testimony of the alleged victim.
(3) The claims that he forcibly kissed women inappropriately is supported by his own bragging on tape that he can't resist kissing beautiful women.
(4) The claims that he grabbed women's genitals is supported by his own bragging on tape that when you're a celebrity they let you do that.
(5) The claims by several women that he ogled while they were changing back-stage of beauty pageants is supported by his own bragging on tape that he goes back-stage at beauty pageants to look at the contestants while they're changing.
It's possible for a person to believe, rationally, that the evidence against Clinton isn't strong enough to assume him guilty, but that the evidence against Trump is. What isn't possible is for a person to rationally believe the opposite. If you're so quick to make assumptions of wrongdoing that you'll do so based on extremely shaky evidence, in the case of Clinton, then the case against Trump should easily pass that threshold.