That seems to be the leftist refrain. But it really ignores two important ideas- First, Biden is not above the law, and is not exempt from investigation; and secondly, Biden is a candidate against twenty other Democrats running for president. If Biden were found to be corrupt, it is in the interest of all the Democrat candidates and their supporters, too.
The other refrain seems to be that the President must explain his decisions of everything he does in foreign policy to low level bureaucrats or they are not legitimate.