RISON, Ark. — Bill Clinton is coming to Arkansas to appear at four rallies for the campaign of endangered Democratic Sen. Mark Pryor. Democrats hope Clinton’s visit will change the dynamics of a race in which Pryor has trailed Republican challenger Rep. Tom Cotton in eight of the last ten polls, going back to the summer. After all, Clinton remains a huge presence here in Arkansas; even though he lives on the global stage, he’s never really left this state, not just with his visits, but the Clinton Library, the 2012 re-naming of Little Rock National Airport to Bill and Hillary Clinton National Airport, and evidence everywhere of his 12 years as governor and eight as president. Clinton put Arkansas on the map, and everybody knows that.

But the Clinton factor in today’s Arkansas Senate race may be difficult to calculate. Of course Clinton will attack Cotton on the stump, but Cotton is appealing to lots of Arkansans who once voted for Clinton, either as governor, or president, or both. To some of those voters, there’s a certain continuity between supporting the moderate Democrat Bill Clinton, beginning when he was first elected governor in 1978, and supporting Cotton today. In a state that has rapidly switched from blue to red, they believe they have stayed the same, while the Democratic Party has changed. So for a young, ambitious Republican politician, it might not be a good idea to attack the man so many Republican voters once supported. And indeed, in an interview on his campaign RV as it bounced along the bumpy roads of rural Arkansas, Cotton not only refrained from attacking Clinton, he went out of his way to compare Clinton’s legacy favorably to the record of President Obama.