How a Uniter Became a Divider

... a review of recent political history reveals that the George W. Bush campaign of 2000 advanced an agenda of “compassionate conservatism” designed specifically to reach out to Catholics, moderate voters and, most importantly, Hispanics. As governor of Texas, Bush was known as a candidate who appealed for support far beyond the GOP faithful. 

What happened to induce such a radical change in GOP thinking? 

In order, the Florida recount of 2000, the Sept. 11 attacks and then Iraq and its aftermath all combined to create an increasingly polarized electorate that caused both parties to focus on incremental gains and large partisan turnouts as the way to electoral success. 

... Then came the 2004 presidential election. Faced with an increasingly unpopular war, the Bush campaign circled the wagons and adopted the only strategy available:
 
It focused on identifying and turning out massive numbers of conservatives and Republican faithful to eke out a narrow victory. This was a substantial accomplishment, but the question remained whether the strategy could be replicated in other circumstances.