In an attempt to kill him, and ensure his reign as king, Claudius kills his wife in the process. He shows no remorse or care to the events that have taken place, this is evident in act V, scene ii, line 306, when he recognizes what has happened, "It is the poisoned cup, it is too late." He realizes that she is about to drink poison but doesn't even attempt to save her, instead he allows her to die. To save her would be to bring his murderous plot out in the open, so he says nothing, trying to salvage his plan. The wanting of power had overcome him much that he was emotionally numb. He cared only about himself, and how to keep himself in the control of things. In the end Claudius sacrificed his entire family to have a fleeting moment as king. .
It's my honest opinion that the majority of people would like to be powerful and have control over things, but for some people that desire grows and grows, getting stronger every day until they just can't control it any more. In certain cases, people are just simply tired of not having any power or control. They are bored of living a life in which they take orders, instead of giving them. So they devise a way to further themselves. In the extreme of cases, a person may go so far as to ruin another person who may be competition or imposing a threat to them taking a position of power.
It stuns me to notice this human characteristic, that for the sake of power, people will put themselves above everyone and everything else. I can't understand how and why people can become so blinded by there own wants and desires they can't see what is really important anymore. Like Claudius, he was just blinded by his desires and in the end lost things that were even more important then power. .
In a few instances, there are people who allow themselves to become so enraptured by the longing for power that they go to exceedingly desperate measures to get it.