(AP) — Republicans are on the offensive in the opening days of Georgia's general election Senate campaign, hammering Democrat Michelle Nunn as a rubber stamp for President Barack Obama and questioning her resume as a non-profit executive — the very experience that anchors her appeal as a moderate who gets things done without partisan wrangling. Ending Spending Action Fund, the conservative political action committee, is backed by Joe Ricketts, founder of TDAmeritrade and owner of the Chicago Cubs baseball franchise. Nunn has embraced the comparisons of executive experience, echoing attacks Perdue weathered from his Republican rivals who lambasted him for presiding over layoffs and outsourcing jobs overseas. She already had to run in a state Obama lost twice — even if by much closer margins than the rest of the Deep South — and where he remains unpopular among white voters who still make up about 60 percent of the electorate. [...] Perdue's victory over Kingston takes away her opportunity to continue her "outsider" campaign against an 11-term congressman. Yet she also talked more specifically this week about the details of "common-sense" immigration reform, which she said should include both tighter border security — a favorite Republican component — and a "pathway to citizenship over time" for people already here illegally, a nod to liberals she has often avoided. At the Democrats' national Senate campaign office, spokesman Justin Barasky skewered Perdue for "a record of tearing apart companies and communities by slashing thousands of jobs." Georgia Democratic Party Chairman DuBose Porter compared Perdue to Mitt Romney, whose wealth — and comments about it — became a liability for the 2012 Republican presidential nominee.