Isn’t the expression, "I'm not inclined to be a supporter of Newt Gingrich's having served under him for four years” confusing?

I found the following line in today’s (December 4) Time magazine article titled, Coburn Speaks Up:

“On "Fox News Sunday," Sooner State Sen. tells Chris Wallace he would have trouble supporting Gingrich. Coburn: "I'm not inclined to be a supporter of Newt Gingrich's having served under him for four years and experienced personally his leadership. I found it lacking often times."

To the eyes of a non-native English speaker, and as a bigoted septuagenarian, Coburn’s remark looks as if Newt Gingrich has served under Coburn and Coburn experienced personally how excellent Newt Gingrich’s leadership is.

Is it wrong to say:

"I'm not inclined to be a supporter of Newt Gingrich's. Having served under him for four years and experienced personally the lack of his leadership, I found it lacking oftentimes,"

though the repetition of 'lack' might be redundant?

Technically, the only thing missing is a comma:

I'm not inclined to be a supporter of Newt Gingrich's, having served under him for four years and experienced personally his leadership. I found it lacking often times.

However, it's still a bit awkward in places: a name ending in 'ch' looks strange and unpronounceable with a possessive tacked on, that misplaced "personally" bothers me, and "oftentimes", besides being one word, is just a redundant way to say "often".

Your correction is on the right track, but you've replaced a missing comma with a couple of incomplete sentences. Instead, I'd rewrite it as:

I'm not inclined to support Newt Gingrich. I served under him for four years and personally experienced his leadership. I often found it lacking.

This doesn't use any complicated grammatical constructs, but still gets the same ideas across.

I don't rate any of the phrasing too highly, as it all seems a bit clumsy.

Grammatically speaking there must be a comma after Gingrich's.

Unless it's OP's transcription error, oftentimes should have been one word.

I personally wouldn't use the possessive for Gingrich's. In such a convoluted sentence it's just one more distraction from clear communication, since until we've read ahead we don't know if it refers back to "supporter", or forward to something coming later - such as I'm not a supporter of Gingrich's views on abortion.

It's only speech, so one shouldn't judge too harshly. Besides which the clunky phrasing is made much worse by a semi-literate journalist's transcription thereof. But if it were to be recast, perhaps some minimal changes towards a better version might be...

I'm not inclined to support Newt Gingrich, having served under him for four years and experienced personally his leadership, which oftentimes was lacking."

But I still find something unsettling about a statement simultaneously claiming to have experienced something, while at the same time saying it was "lacking" (ie - "wasn't there").