Doesn't feel right...
Seems to miss the point, like Protestant Kennedy's. Since this is slightly ASB, and me keeping him Mormon big ASB, I will make it interesting. 1st POD: McKinley not shot. 1908 Teddy versus Big Business Candidate, splitting Republicans (like 1912), leading to a WJB ("something" Jennings Bryan) election. A religious man, he hears some Mormons are still committing polygamy (offshoots). He sends out lawyers, but when the polygamists hide, US Marshals and the US Army. Also he puts pressure on the main Mormon church. They, fearing it is 1830-1857 again, maintain the colonies in Canada and Mexico at all costs. Mitt's grandfather relunctantly agrees, and to be safe renounces his US citizenship.
The Mexican civil war starts on cue, bad news for all. Grandfather (don't know his name; he ain't mine!) holds the farm (?) and local towns together, taking the side of no violence, but no judging, leading to refugee Indians (what are Native Mexicans called? In the US Native Americans?), Pacho Villa's men, and Mexican refugees all mingling together in a tense peace. (I realize the Native Mexicans were farther south, just trying to have the family have a reputation of helping all in need).
When the war is over, the Romney's are at the center of a small boom, mainly in construction; young George Romney (Jorge? Can't speak a lick of any language, sorry) helps out (happened OTL in America). He runs for governor of a northern state (as others have pointed out), winning it sometime in the late 1950/ early 60s (the dates are of no concern to me; someone else can turn this into gold), getting some factories built.
Also pushes for equalish rights for Mexicans and Native Mexicans (really need to know what their name is...). In OTL, he did care about black housing in Detroit in the 1950's, I believe.
Although eventually kicked out of the PRI, he still wins reelection due to his hard work in solving problems, working class background, and religious nature (here meaning he is honest, helps others, etc... no one like Mormons, they just like him). He retires and fades from my story.
El Mitt (do we have a name for this alter ego yet?) studies business in America I figure (1, have a campaign attack that he is a Yankee in disguise, and 2, I think the US is better for business right now. Any Mexicans/knowledgable [spelling again!] just pick a non Marxist business school for him in Mexico). Since this is pretty ASB, lets say he goes into banking, lending only to Mexican businesses (using legally the the Mexican oil company profits as capital? Like GMAC), and travels around Mexico. He also marries a (Mormon) Mexican wife sometime. Remembering his father's stories about the poor Indians, he spends extra time there trying to get their economy going (trying to get him support for the 1994 revolt/riot/thingy (I was 9 at the time, so not too sure what is was, and have to get to bed soon. Will wiki Monday). A key moment for him was when he and his father helped Mexico get a sweetheart deal on the 1994 peso "bailout."
Even with this, we still have to get him elected. So in 1998 he announces that he will run for President against the PRI for the 2000 election. He has to be a lot more conservative than OTL (his dad and mom [if mom like OTL] too). Does Mexico have VP's? He needs to be solid, preferably a beloved Catholic Bishop/Cardinal/Saint (Mitt needs the help).
Mitt in real life (sounds like a boring movie) seems to like solving problems, so he needs to push that big time: I will make NAFTA pay for Mexico, increase the standard of living here, solve technical problems, while my Cabinet deals with Mexican culture.