What if the Roman Senate was elected?

What do you think the Roman Empire would have been like if the Senators were elected by the people annualy instead of being appointed for life. Do you think that the Roman Empire would have been different do you think that maybe it would have stayed an aristocracy or would it have been a true republic? All comments please be respectful and knowledgeable I hold considerable knowledge of the Roman World so all know if you don't know what your talking about.