That Obama's father was an extreme Leftist who hated the British is a matter of record but the Leftist writer below finds all sorts of deep and devious reasons why anybody would mention that.
How about a really simple reason: Obama was obsessed with his father (He authored a book called "Dreams of my Father") so it is reasonable to suspect that he has similar views to his father. It is after all not at all unusual for fathers and sons to have similar views -- though there are exceptions to every rule of course
"Huckabee, to the surprise of most everyone, started squawking that President Obama grew up in Kenya, where he was influenced by his father’s and grandfathers’ anticolonial Mau-Mauism to despise the British Empire—and, by implication, all white power.
Only after being called out did the Fox News host say he “misspoke” on the growing up in Kenya part
All this garbage started last year with Dinesh D’Souza’s repulsive headliner for Forbes, which maintained that Obama’s “anti-business” policies could be explained only by his “Kenyan anti-colonialism.”
But here’s a simpler theory: The right spews this bizarre “anticolonial” claptrap because it gives them a chance to say “Mau Mau,” which conjures a more fearsome threat than the N-word itself.
The Leftist writer above would probably not have known this but political attitudes are to a considerable extent genetically inherited. Even if a son knew nothing of his father, he would still be highly likely to have similar political views to his father. If your father was a miserable whiner, you are likely to be a miserable whiner too.
Update. Two small personal notes
I suspect that I got my political values from my father. He was a kindly man but hard work was his religion. "Bludgers" were the lowest of the low to him. He would have regarded the welfare parasites who infest most of the developed word today as not much better than maggots.
And my son is also conservative, though less emphatically than I am. He has however recently moved to an elite university to do his doctorate in mathematics and that university is a hotbed of socialism. So he has quizzed some of the socialists around him and is amazed at the shallowness of their thinking. So encountering real socialists has definitely moved him in a direction that I approve of.