(AP Photo/Mahmoud Illean, File)JERUSALEM – After a hard-fought election, an Arab Islamist could choose Israel's next prime minister. That means the United Arab List, known by the Hebrew name Ra'am, could decide whether Netanyahu, Israel's longest-serving prime minister, remains in office. If so, he succeeded, convincing Mansour Abbas, the leader of the United Arab List, to run a separate list. Arab parties have never asked to serve in an Israeli government or been invited to do so. Israel's Arab citizens have close family ties to Palestinians in the West Bank and Gaza and largely identify with the Palestinian cause.