Judging most of the inhabitants of Iraq to be Shi’ah is not accurate, because most the statistics that we have now are old and not very accurate. Even some modern statistics demonstrate the opposite, based on studies of some provinces.
Whatever the case, if what is being given to the Raafidis is the obligatory zakaah then we have already explained the ruling on that in question no. 1148. But if what is being given is voluntary charity, then the scholars have stated that it is permissible to give voluntary charity to kaafirs.
It says in al-Umm: Al-Shaafa’i said: There is nothing wrong with giving voluntary charity to a mushrik, but he has no right to any of the obligatory charity (i.e., zakaah). Al-Umm, 2/65.
It says in al-Mughni: All those to whom it is forbidden to give zakaah, such as the rich, close relatives of the giver, kaafirs, etc, it is permissible to give them voluntary charity and it is permissible for them to take it. Allaah says (interpretation of the meaning):
“And they give food, in spite of their love for it (or for the love of Him), to the Miskeen (the poor), the orphan, and the captive”
And at that time captives could only be kaafirs. Al-Mughni, 2/277.
But if the money that is donated could be used for sinful purposes or to harm a Muslim, then it is not permissible to give it to a Muslim, let alone to a follower of bid’ah or a kaafir.
Based on the above, if you are certain that this money will reach people who will use it to harm Muslims, it is not permissible to give it. You can look for other ways of giving it to those who are more entitled to it.
It is better for a Muslim to give his zakaah to people who obey Allaah.
Shaykh al-Islam Ibn Taymiyah said in al-Ikhtiyaaraat (p. 103): Zakaah should not be given to someone who will not use it to help him obey Allaah, for Allaah has enjoined it as a means to help people obey Him, to be given to those believers who need it, such as the poor, debtors or those who will help the believers. A needy person who does not pray should not be given anything until he repents and prays regularly on time.
And Allaah knows best.