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.
For example, how do you react to inherently unfair situations, someone taking advantage of someone else? If you start picking on people good politicians will quickly “plausibility deniability” you out of the equation.
It’s much easier to accept (with a bit of anger) that you made a mistake in your program that bring defaced due to your “judgement being clouded by anger”.
You may be smart enough to even understand what you have to do, but it will take practice to do it well even if you understand it conceptually.