She was SOS until February 2013, before the bs Russia story. Not much chance of it affecting the election, but it still stuff we need to see.
Yes, it's stuff the public should see. However...since we don't know what the 33k emails were about, such a statement can't be definitively made.
One example...it's certainly possible and in fact likely, that Biden (VP during clinton's SOS tenure) is mentioned/implicated in one of at least 1/2 a dozen wrongdoing's/crimes during that time.
Would such a revelation affect Trumps base and their vote? No.
Would it affect Biden's base and their vote? Certainly not the anarchist's/communist's/socialist's/hollywood types, possibly the "blue dog" dems.
Would it affect the fence sitters and undecideds out there, some of whom wait until they're in the voting booth? Perhaps yes.
Therefore, it's possible such a release of information could make a significant difference in the election, down ticket included.