The two most prominent religions are Islam and Zaydism.  It’s hard to get your arms around exactly what Zaydists believe (kind of like most religious people in this country), but here is a sample:

Zaidi beliefs are moderate compared to other Shi'i sects. The Zaidis do not believe in the infallibility of the Imams, nor that the Imams receive divine guidance. Zaidis also do not believe that the Imamate must pass from father to son, but believe it can be held by any Sayyid descended from either Hasan ibn Ali or Husayn ibn Ali.

Zaidis believe Zayd was the rightful successor to the Imamate because he led a rebellion against the Umayyads, whom he believed were tyrannical and corrupt. Muhammad al-Baqir did not engage in political action and the followers of Zayd believed that a true Imam must fight against corrupt rulers.

Need I say more?