By Jon Keller

BOSTON (CBS) – It isn’t easy being a professional politician.

They get hit with sharp elbows all the time by wise guys, yours truly included. They can never get what they want done, and whatever they do get done can never make everyone happy.

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And they are constrained by intense public focus and skepticism. A political consultant I know says he tells first-time candidates they can no longer react to getting cut off in traffic; someone will see or hear them, and their moment of temper, however justified, will become a damaging news story.

As all Massachusetts drivers can attest, that is one onerous restriction.

But after watching short-fingered vulgarian Donald Trump announce his temporary presidential candidacy Tuesday, we ought to give thanks to the professional politicians – the well-meaning ones, at least – for the restraint they practice, however unwillingly at times.

Donald Trump announces his candidacy., June 16, 2015  (Photo by Christopher Gregory/Getty Images)

Donald Trump announces his candidacy., June 16, 2015 (Photo by Christopher Gregory/Getty Images)

I am a big advocate for more honest talk from our political leaders, but Trump mistakes rudeness and narcissism for honesty. To him, all other candidates are without “a clue,” all critics are “losers and whiners.”

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Illegal immigrants? They’re mostly “rapists” who are “bringing drugs” and “crime” with them. Although, he concedes, “some, I assume, are good people.”

There’s a reason why business executives like Trump rarely make good candidates – they’re used to an audience of yes-men.

So let’s pause to praise the professional pol – OK, that’s enough, now back to elbows as usual.

Listen to Jon’s commentary:

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You can listen to Keller At Large on WBZ News Radio every weekday at 7:55 a.m. You can also watch Jon on WBZ-TV News.

Jon Keller