Watching the Democratic Convention last night, my daughter asked, “Why would people in their last years of life run for president?” 
I thought that was very telling. Rather than assuming being the top dog as a good thing, she sees it as a burden and a responsibility. Why do people strive to get to the top in all disciplines of life? And is it always greed for power and fame and thus it should be denounced? 
I think the DESIRE to get to the top for power and fame is always bad. However, the desire to serve God in whatever capacity is good. And this might mean that we become the boss, CEO, or the president. 
“So, whether you eat or drink, or whatever you do, do it all to the glory of God.” 1 Cor. 10:31

• Joseph became the prime minister. But he didn’t strive for power and fame. He strove to serve God.
• Moses became the de facto leader of a nation. But again, he didn’t strive for power and fame. He strove to serve God.

But there is always the caveat. Sometimes we desire a certain position to sincerely serve God in that position. However, when we get there, we often forget God and simply enjoy the benefit that comes from that position. An example of this is King Saul – the very first king of Israel. Although humble in the beginning, once he became king, he employed evil means to keep his position. 

Ask yourself. Why do you want that position really? Is it for you or is it for God?
Here’s a test: Can you pray, “God, only if it will serve your purpose, give me this position.” 
Growing as a Christian means learning to connect everything we do to God. 
PH
p.s. To answer the question, “Is it always wrong to want power?”, I would say “no.” It is good to want ‘spiritual’ power.  (Eph 1:19) And that spiritual power is always used for others.