Here is an old scenario of mine about how to make GW Bush president in 1988:
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1978--Dubya narrowly defeats conservative Democrat Kent Hance in race for Texas 19th Congressional District. He is re-elected in 1980 and 1982.
(In OTL, Hance won a fairly narrow victory. How to change the result? Well, for one thing, don't have the divisive GOP primary where Jim Reese presented Bush with a strong challenge which made the race seem like a proxy for the forthcoming Reagan-versus-Bush-senior presidential race. Or at any rate, after the primary, have Reese back Bush more enthusiastically. Also, have Bush counterattack when Hance brings up the Texas Tech "Bush bash" which featured--horror of horrors--*free beer*. See
http://www.nytimes.com/library/politics/camp/072700wh-bush-lubbock.html for an account of the campaign.)
1984--Crazed "lone gunman" (who claims he is trying to impress Brooke Shields) kills vice-president George Herbert Walker Bush. President Reagan surprises everyone by naming Bush's son, Congressman George W. Bush, as vice-president. (After just a few terms in the House of Representatives? Well, Mondale after all would soon name Geraldine Ferraro as *his* running mate--and *her* experience in national politics was limited to a few terms in the House.) Reagan explains to aides that Bush is from a key state and will provide both youth and "continuity" in the vice-presidency. He jokes that "we won't even have to change those Reagan-Bush buttons from 1980." Reagan-Bush ticket easily defeats Mondale-Ferraro in general election. (Incidentally, Dubya would not be the youngest vice-president in US history--that honor goes to John Breckinridge.)
1988--Vice-president George W. Bush wins GOP presidential nomination over divided opposition (Dole, Kemp, Robertson, several others). For his running mate, he knows he needs someone considerably older and more experienced than himself, and chooses a Senator from Indiana--Richard Lugar. The Democrats nominate Michael Dukakis to oppose Bush. Dubya runs as a "compassionate conservative," promising a "kinder, gentler America." When his youth becomes an issue, he points out that he is not substantially younger than JFK or TR when they became president. Dukakis snorts, "We in Massachusetts knew Jack Kennedy, and Mr. Bush is no Jack Kennedy."...
Thanks to peace and prosperity and an inept debating performance by Dukakis (who stumbles badly on a question about how he would feel about capital punishment if his wife were murdered), Bush wins by about 52 to 48 percent (a little worse than his father would do in OTL--the "youth and inexperience" issue did hurt somewhat).
Shortly after the election, Bush starts naming his Cabinet, including his old House colleague Dick Cheney of Wyoming as Secretary of Defense...
https://groups.google.com/d/msg/soc.history.what-if/CHIhVWyBQx0/ozOqghXqifcJ
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After that, GW Bush is defeated by Bill Clinton in 1992 for roughly the same reasons his father lost in OTL...