In 1989 newly elected President George H.W. Bush selected former Texas Senator John Goodwin Tower as his pick for Secretary of Defense. The nomination proved to be controversial due allegations of conflict of interest, alcohol abuses and womanizing but at the end the Senate narrowly voted to confirm Tower. Actually the Senate deadlocked and the Vice-President Dan Quayle used his powers to cast the decisive vote. Tower went to be reminded as a major hawk during the Gulf War.
However Bush later said that he didn't believe Tower would get confirmation and was planning to nominate Rapresentative from Idaho Richard "Dick" Cheney, who had won Republican House Whip Chair just two months and half before.
Cheney went to become Speaker of the House after Republicans retook control of the Congress in 1994 but he stayed as Speaker for less then two weeks, before becoming President after the President Clinton, Vice-President Gore and Pope John Paul II's deaths during the 15th January Attacks (the infamous Operation Bojinka).
As all we know President Cheney declared a "War against Terror", passed the Patriots Acts, created the Homeland Security Agency, picked many conservatives in Supreme Court and invaded Iraq, Yugoslavia, Syria, Lybia, Somalia and North Korea. Cheney was widely criticized as his invasions seemed be more linked to arms and oil companies' interests then to a sincere humanitarian ambition (for example Rwanda has one of worst genocide of recent history and never saw a single Marines) and his security laws were accused to be authoritarian and unconstitutional. During his Presidency (1995-2005) the Democratic Party moved towards Pacifism, Isolationism and leftwing economic policies, the Republican Party had a schism when Powell, Bloomberg, Nunn, Weld and Johnson, the so called Gang of Five, formed the New Whig Party and America lost many allies. He left the office and secluded himself in his home-bunker in Idaho, persecuted by claims and allegations that he orchestrated the Bojinka Attacks in order to become President, before dying for an heart attack in 2015.
Now, what a single Senator chooses to vote Nay in 1989 and Bush nominates Cheney?
Probably he will never become Speaker and so President. Could he find a new way towards the White House? Who replaced Cheney as Whip, Speaker and presumably as President? How evolved America and the World without Cheney?