Earlier quoted context omitted.
One would think that being smart should be an asset when playing politics, though.
Politics require social skills, being smart is detrimental because it lets you see thru all the bullshit.
Many smart, principled people aren’t able to sufficiently lie to themselves or feel comfortable using ambiguous terms and/or outright lying, and that hampers their ability to covertly send and receive signals to others, so others who are successful at politics would do well to stay away from them. You have to compromise in order to get things done, but it doesn’t behoove you to lay out all of your cards for everyone to see.