The reality is that as he aged, he would’ve lost the youth following that helped spark the civil rights movement. He would’ve been considered a relic of a sort and his thinking not suitable for the new climate of the day (70s and beyond). That pushback would’ve been almost simply because he was so revered and famous.
However I would like to think that King would’ve have been dynamic enough to keep the youth invigorated with his thinking and the movements he was taking on. Most of us weren’t there to speak on it but when older folks speak on King, not too much follows that gave them a similar passion. Most folks just got to working.
If he was alive or able to live a longer life, maybe that passion stays and takes root in the following generations....