Historically, most totalitarian states that have emerged from democratic/republican rule do so by enumerating some sort of threat, and giving "emergency power" to stop it. Whether or not a timeline is placed on neutralizing such a threat is basically irrelevant. Once a person has that sort of power, it is not a difficult matter to cite examples of the continuing threat as a motive for continuing power. Adolph Hitler is, perhaps, the most famous example of a practitioner of this strategy.