> would make more sense

That is truly a god-awful piece of confusing crap! There is little clue as to what each referent might be (father or son?!) and the grammar is tortured in its confusion of tenses. I *think what is intended is a meaning something like this – but I could easily be wrong!

“I think it was a big problem for TR to know what to do because all through his life he believed himself to be an inferior human being to his father. In part he was motivated to go into politics precisely because his father had been defeated in politics: that was his father’s one defeat, confirmed by being beaten by the bosses in a brief foray back into politics at the end of his life. This was therefore the one thing the son could do that his father did not succeed at: TR could beat the political boss.”

hth!