Yes, I have seen it written that Kerry "recruited" Walinsky to write the speech.
If I had wanted Walinsky to write a speech for me in 1971, I don't imagine that it would have been possible.
It's more likely that Walinsky recruited Kerry.
Interestingly, Walinsky was a principal author of the 1965 Immigration Reform Act, often attributed to Edward Kennedy.
Walinsky's hatred of America and her people must have been established at a very early age.
Kerry was keen on assuming the Kennedy mantle. As for the Reform Act, Walinsky at the time was a chief legistlative aid to Robert Kennedy. The attribution to Ted was no doubt a throwaway to boost the prospects of the litter runt.