Prince Felix Yussupov thought killing Rasputin would save the monarchy. Exactly the opposite happened. Most historians believe Yussupov fired the first shots of the Russian Revolution. Order could not be restored in St. Petersburg. (This link takes you to the famous Church of the Resurrection.) The Tsar was convinced the only thing holding the Russian Empire together was the monarchy. He grossly miscalculated what the people wanted.
Had he talked to his subjects, he would have understood the desperation of the poor. Had he visited some of the factories, he would have seen the terrible conditions. But Nicholas was raised in the Imperial Family where monarchs (like
Peter the Great) wielded power over, but didn't talk to, their subjects. Unless it was expedient, rulers rarely looked at the living and working conditions of the ruled.
Nicholas was insensitive to vast changes sweeping through Europe. He failed to grasp that his country, the mighty Russian Empire, also needed some measure of change. His inflexibility was a direct link to his loss of the throne. The Russian system was beginning to fail, but Nicholas didn't see it. Once the momentum of radical change began to build, Nicholas was powerless to stop it. He had missed his opportunity to bring about peaceful change in the country his family had ruled for 300 years. By insisting on old ways of the past, he wrote himself out of a place in the future.
Earlier, he had left St. Petersburg for the more tranquil setting of Tsarskoe Selo and Peterhof. He wanted to avoid the unrest in the city. But soon unrest found its way to him.
Close friends and advisors told Nicholas to abdicate. Realizing he had no other choice, he abdicated for both himself and his ill son. (Note the double-eagle Romanov seal at the top of the abdication letter.) Nicholas directed that his younger brother, the Grand Duke Michael, would become Tsar.
Writing to his brother, Nicholas referred to Michael as the new Tsar. Michael proposed terms by which he would agree to assume power, but
his manifesto (follow this link to his proposal) was not accepted by the provisional government.
Michael was Tsar for a day. The next day, the monarchy was finished - declared dead by the provisional government. By the summer of 1918, Michael himself was dead - murdered by the Bolsheviks.