It's always like that because, unfortunately, negative campaigning works. Throw enough mud, and some of it inevitably sticks.

This year has been good for one thing, however. It has shown us exactly how irrelevant the party conventions are. When the candidates are already known once primary season is over, and since the party platforms (the only other reason to have the conventions) are irrlevant to most voters anyhow, why bother? Both major parties have already indicated that this year's conventions will probably be the last ones to be held in major cities (security concerns), and will also be the last ones to be held for four days.