The problem with ISIS is their beheadings, slaughter of innocents, destabilization of countries, piracy, and persecuting minorities. Not their support of Islam.
The problem with Iran is their development of nuclear weapons, their ballistic missile program which now extends in range to cover the Europe, their support in weapons, money and training of various paramilitary groups such as the Houthis, Hezbollah, Hamas and Islamic Jihad, their oppression of their own citizens, hanging gays from cranes, various bombing and attack operations (US forces, Saudi facilities), attacks against oil tankers and calls to annihilate Israel. Not their support of Palestine.
Now ask yourself, how much of that list is the US or Israel also guilty of an equivalent crime? Supporting Palestine is one of the few things that seperates them.
The problem with Iran is their development of nuclear weapons, their ballistic missile program which now extends in range to cover the Europe, their support in weapons, money and training of various paramilitary groups such as the Houthis, Hezbollah, Hamas and Islamic Jihad, their oppression of their own citizens, hanging gays from cranes, various bombing and attack operations (US forces, Saudi facilities), attacks against oil tankers and calls to annihilate Israel. Not their support of Palestine.