How Could a Continued Line of Rashidun Rightly Guided Caliphs Happen after Ali? No Omayyad Line occurring...
My guess is that most likely, when the Uthman's reign were gathered in Palestine from Egypt to attack Medina, Uthman could have ordered his trusted governor Muawiyah to attack the rebels. The rebels carried a forged seal of the Caliph, but there was much proof that it was a fake. Ibn Saba, Mohammad ibn Abu Bakr, and Muhammad ibn Hudhayfa, and all the other instigators could have been captured and dealt with effectively.
Without those men (and other prominent rebels, such as Malik Ushtur etc.) there was not much opposition to Uthman's rule. He could have died, and passed the Caliphate onto Ali, and Muwaiyah never would have challenged Ali. His excuse for challenging Ali was the deaths of those who killed Uthman, but Uthman lives in this scenario. Muawiayah was a capable statesmen and diplomat, and a holder of the strong Byzantine frontier. He could have suceeded Ali without much trouble, or the Caliphate could have passed onto Talha ibn Obeidallah or Zubayr ibn Al-Awwam, both who were close companions of the Prophet, and able statesmen and pious men. And from thereonwards the Caliphate could remain an elected position, but for how long?
Your take?