An Imitation Tet Offensive as an October Surprise
If the loons running Iran wanted to swing the Congressional election over to the Party of Surrender and if they had widespread support in the Shiite areas of Iraq, they could probably start an imitation Tet Offensive designed to disrupt the U.S. Army's supply lines between the Persian Gulf and Baghdad. If they don't, that might be evidence they don't have any local support.
Even if they started one tomorrow, that would mean they don't think they can sustain such an offensive for more than two weeks. If they thought it could last longer they would have started it already.