Hearsay

So I heard that Uncle Joe Biden like to fondle women without their permission. And that he has paid off several of them/
Does this mean that we can toss him out of the running for president?

I mean, really, So far, all I have heard is a whisper campaign and a bunch of repeated gossip and allegations, (much like a bunch of 9th grade girls) but no solid testimony and no first hand knowledge. 

Why is hearsay accepted as evidence here?