LBJ died in early 1973, and had he been President after 1969, the stress of the job would’ve killed him before that. He was only 59 when he announced he wouldn’t run in 1968 and he already looked like an old man. Reagan was only 2 1/2 years younger than LBJ when he attempted to run for President in ‘68 (just 57) and was pretty energetic and fresh-faced by comparison.
Humphrey, too, died in early 1978 (while serving in the Senate) and also wouldn’t have survived the stress of the Presidency.
LBJ’s notorious drinking, smoking, and atrocious diet didn’t do him a bit of good, either.
Three packs a day for many years. And just LOVED Cutty Sark.