Well, campaigning on welfare is basically how the GOP played its southern strategy and stoked racist fears. Welfare and race are inherently intertwined in people's minds. That's why.
The Southern Strategy was not meant to stoke racist fears through code words or otherwise. According to Pat Buchanan, the architect of the Southern strategy, it was an attempt to convince Southern moderates who were pro-civil rights to vote Republican as a protest against the racists and segregationists in the Democratic Party:
http://www.wnd.com/2002/12/16477/
That is only slightly more credible than John Edwards explaining away his support for Rielle Hunter and flies in the face of all evidence as to how the Southern strategy actually worked.