The word 'politician' often brings a negative connotation to many people. Politicians are known for being deceitful. They use every possible means to get what they want or aim for--ethical or unethical. Based on these terms, Churchill was most definitely not a politician.
The difference between a politician and a statesman can be compared to the difference between values and principles. For example: the belief that terrorism is wrong is a value, but the fact that America rallied together to fight it worldwide is a principle. Here is an example of how President George W. Bush was a statesman not a politician. Winston Churchill believed that Germany was building up a massive army to prepare for a large-scale war; that's a value. But he also believed that Britain, among other nations should and must prepare to resist Hitler's army and put him in his rightful place; this is a principle, a principle which he carried out to the best of his ability. He gathered as much information as he could and put it together to convince the government of Britain that the nation of Germany posed a great threat and could invade at any time. That is what qualifies Winston Churchill is a statesman.
Although, once the situation with Germany was realized, there seemed to be no hope or positives to look at, Churchill brought out those positives and gave the people the spark of hope they needed to begin to bear arms. But he still maintained the seriousness of the situation letting people know that it's no light matter.
A true statesman should also demonstrate shrewd thinking. Churchill displays his shrewdness when the people of France are yelling, "Negotiation, negotiation!" as Germany attacks. He discerns Hitler's motivation and sees that what he wants is control whether he gains it by force or through surrender. No amount of 'negotiation' or petty appeasements will satisfy Hitler. Therefore, war, as Churchill concluded, is inevitable.
While a politician is out for personal gain and power, a statesman sees the bigger vision and a purpose greater than himself. Churchill's motivation for preparing for war was not for power and control of territory but for the freedom of the people of Britain and other nations. This is an example of his moral character.
Unlike the cowardly politician, Churchill showed his statesman-like courage by continually trying to convince others that war is inevitable with Germany. Even after he was voted off the government council, his work continued all the same. No matter what the persecution was, he didn't let that stop him.
There is no doubt Winston Churchill was a history maker. Without him, Germany may have won the second World War, and none of us would have the privilege to be free. And it was all because he saw the need and a cause greater than himself and acted on it.