Miari was born during the Mandate era in al-Birwa, a village which was depopulated as a result of the 1948 Arab-Israeli War.

He grew up in Makr and attended high school in Kafr Yasif, and was also a member of the Arab Youth Pioneer movement.

He lost his seat in the 1992 elections, in which the PLFP won only 0.9% of the vote, failing to cross the 1.5% electoral threshold.

During his time in the Knesset, there were two attempts to remove his parliamentary immunity; one over his attendance at a meeting in memory of Fuad Kawasme, who had been removed from his position as mayor of Hebron, and the second for meeting PLO leaders in 1988 and a press conference at which he expressed support for the First Intifada.

He left Balad in 2014 due to the party's criticism of Bashar al-Assad's conduct during the Syrian Civil War, becoming leader of a breakaway movement named Kapah (Struggle).