There is a distinction that I think a lot of people miss in how a democratic government works. Most people combine evaluations of politicians as 'good' and 'bad' based on criteria which is not important to how they are selected. I make this distinction between statesmanship and politics.
Lets start with politics. I would consider a good politician someone who gets elected. The best politicians are the ones who get elected to the highest office as many times as allowed. Obama, George W Bush, Clinton, and Reagan were good politicians, Reagan was the best of those, from the electoral results. They all were elected to the highest office twice. My statement that these are all great politicians is usually challenged because people confuse 'politician' with 'statesman.'
A statesman is someone who is good at governance. These are the people who are able to make government function effectively. Good statesmen are NOT the same as good politicians. The key problem with the democratic process is that we want good statesman, but we select good politicians, and they are not the same. This is why things whether getting a beer with a candidate are political questions, even if they have nothing to do with making effective policy.