It was Lee Atwater's campaign for HW that nailed it down in public - the conversion of the Republican Party to a fascist political organ. One could, until then, keep some semblance of plausibility while contending that the Republican Party was "conservative", "fiscally responsible", whatever - that Supply Side and Dog Whistle Reagan was an aberration or personality driven one-off. After this "https://en.wikipedia.org/wiki/Willie_Horton the cat was out of the bag. That was what the best and brightest campaign pros, the people who knew what they were talking about, thought would appeal to the voting base of the Republican Party in the most "liberal" regions of the US. In 1988. And they were right. There will be dignified eulogies, if Trump doesn't hog all the press. But HW's legacy is land war in Asia Minor, the crippling of the US via what he himself described as "Voodoo economics", and the racial ugliness of Trump's America. That, and having the US President publicly humiliated by foreign heads of State - becoming a Republican Party tradition: https://en.wikipedia.org/wiki/George_H._W._Bush_vomiting_incident Meanwhile, the political legacy of interest here is probably Barbara "Ma" Bush's.
It never ended. W's continuation made it worse, but on the same trajectory. By not repudiating Reagan, HW brought the "respectable" Republican establishment fully on board in launching what we are now in, continuing the corruption of the military and intelligence services established by Reagan, and the base of false pretenses (Iran, Saudi, etc) that has wrongfooted the US in the region ever since. HW's image of dignity and probity is a mirage, created by comparison with the awful farce of Reagan's second term and W's tenure. He was second generation money and power, remember - the patriarch's son. His father was dealing oil and supplies to Hitler even after 1938, in political sympathy as well as for the money. He hired Lee Atwater - that was not an accident.
A respectful, evenhanded take: http://driftglass.blogspot.com/2018/12/the-partys-over.html which reminds us, at the same time, of the nature of HW's campaigning and Presidency, including this item for those forgetfully ascribing dignity to the HW tenure in politics: HW was the second Republican Presidential candidate to put up a Palin for VP - Nixon had Agnew, HW had Dan Quayle. But Quayle was useful in another way for HW - he said even sillier things, was even more feckless and odd sounding, drawing attention away from the goofiness of HW's verbal offerings. People have forgotten the way that man talked, in unguarded moments - his son W didn't fall too far from that tree.
Oh, come on.. He was sick and then promptly fainted. Having had that kind of gastro (I projectile vomited on my boss in a meeting and then passed out cold), I can assure you, it's not something he would have been able to control or stop.
As the Japanese - for whom arranging such things was a thousand year tradition, hosting an American President who had been a bomber pilot in the Pacific theater of WWI, arriving as a supplicant in trade talks involving what looked then to be a Japanese financial ascendancy - well knew. It was a remarkable coincidence, anyway. Just sayin'. - - - - International diplomacy is hardball. The Reagan Republican Party has handed the US a series of powerful politicians who were basically screwups at it - weak and error-prone, continually forced to resort to threats and actions of military and paramilitary violence even in situations of economic and cultural predominance. And that's giving them the benefit of the doubt - darker possibilities exist. HW was an authoritarian, military oriented, rightwing, Big Oil corporate aristocrat - with all that implies ( HW in 1988 explaining why he opposed a rape exception in laws banning abortion: "{Because} women will lie"). Among the things that implies: diplomatic incompetence as a representative of free people. Fascists do not make the trains run on time.
Another respectful, give the man his due, take on HW: http://www.lawyersgunsmoneyblog.com/2018/12/bush-2
A less respectful - and perforce more complete - take: https://downwithtyranny.blogspot.com/2018/12/another-criminal-dies.html Covering for assassinations of US citizens and protected people by foreigners with corrupt US connections? Check: Collusion with ostensible hostile foreign powers for their help in swinging a US Presidential election, simultaneously coming into some useful cash money? Check: A history of groping women ? Check: https://www.nj.com/news/index.ssf/2017/11/george_hw_bush_eighth_accuser_groping_1992_campaig.html Allied with the very bad guys in multiple circumstances? Check: Odd syntax and phrasing, often not making much sense, accompanied by strangely uncoordinated and asynchronous hand gestures? Check. Surrounded by crooks and fascists? Check. The forty year problem is not Trump. It is the Republican Party.