Mitt Romney aims to add to his substantial lead in the delegate count, but Rick Santorum is strong in Kansas. All the Republican presidential candidates are concentrating on Tuesday's primaries in Mississippi and Alabama.
Mitt Romney and his Republican presidential rivals competed Saturday in caucuses in Kansas and Wyoming, the latest contests in a grinding campaign for the nomination to oppose President Barack Obama in the fall.
A total of 52 delegates to the Republican National Convention was at stake, 40 in Kansas and a dozen in Wyoming.
Romney showed strength in Wyoming counties that picked delegates earlier in the week, but did not campaign in Kansas.
Romney began the day with 440 delegates in the AP's count, more than all his rivals combined. Santorum had 181, Gingrich 107, and Paul had 46. A candidate must win 1,144 to clinch the Republican presidential nomination at the national convention in Tampa next August.