When the Ikwan and Saudis were conquering Arabia, why didn't they either force the Shia to convert, kill them, or drive them out of the kingdom? They were known to slaughter in great numbers, and seemed to have no problem forcing the other Sunnis to convert, so why didn't they force the Shia to do the same thing? I know that in Saudi Arabia they do not allow other religions or sects practiced openly, to include Sufism or other branches of Sunni Islam, so why allow the Shia, even while being heavily persecuted?
Um they allow sufis in Saudi, Abdullah Bin Bayyah is a Sufi that openly engages in Sufi dhikr and is a professor at King Abdul Aziz University. It's not uncommon to have Sufi gatherings in the Prophet's mosque in Medina either.
