According to exit polls, evangelical Christians comprised a majority of 2012 Republican primary voters in Mississippi, Alabama, Tennessee, Oklahoma, South Carolina, Louisiana, and majorities of 2008 voters in Texas, Missouri, and Arkansas (states where exit polls were not conducted last time). Although exit polls aren’t available, evangelicals, based on their share of the overall population, will likely comprise a majority of GOP voters in other Heartland states including Kansas, Kentucky, and West Virginia.
In December, Cruz held only three events in Iowa, but attended 10 in the South.
By contrast, Trump's sole super state visit was to Virginia (one event). Likewise, Fiorina made only one visit to the southern states.
Cruz has devoted significant time and resources to the southern states even at a very early stage of the primaries.