David Brooks praises Lincoln for showing that the “challenge of politics lies precisely in the marriage of high vision and low cunning.”  He elaborates:

The movie is about pushing the 13th Amendment through the House of
Representatives. The political operatives Lincoln hires must pay acute
attention to the individual congressmen in order to figure out which can
be appealed to through the heart and which through the wallet.

Lincoln plays each potential convert like a musical instrument,
appealing to one man’s sense of idealism, another’s fraternal loyalty.
His toughest job is to get the true believers on his own side to
suppress themselves, to say things they don’t believe in order not to
offend the waverers who are needed to get the amendment passed.

Suppose Brooks’ claims are factually correct.  What economic, psychological, and/or sociological model(s) would explain them?  Why precisely would good political ideas need to be shrouded in deception?  Or is the claim that all political ideas needed to be shrouded in deception?  If so, why would this be so?

As the author of The Myth of the Rational Voter, I know where I’d start, but I’d like to hear sometime else talk.  What would Brooks himself say?