Dem poll: Donnelly leads Mourdock in Indiana

Donnelly proved himself a tough campaigner by hanging onto a Republican-leaning seat in the GOP wave election in 2010, although his fundraising so far has been less than stellar: he raised just $220,000 last quarter and had $850,000 in the bank.

Despite the polling, national Republicans argue either candidate will have an easy time against Donnelly.

"The two things he's noted for are the Stimulus and ObamaCare," said National Republican Senatorial Committee spokesman Lance Trover. "ObamaCare is an issue that's on people's minds and is not going away, and there are polls that show the vast majority of people oppose this legislation. I think this is going to be a big issue in this race for Joe DonnellyJoe DonnellyOvernight Finance: Senate punts on Zika funding | House panel clears final spending bill | Biz groups press Treasury on tax rules | Obama trade rep confident Pacific deal passes this year Overnight Healthcare: Lawmakers leave for summer without approving new Zika funds Dems block defense spending bill for second time MORE to deal with."

Lugar has been beset by problems this month, some of them self-inflicted: he's repeatedly struggled to get past questions about his residency that stem from him not owning a home in Indiana for decades. The National Rifle Association has also endorsed Mourdock, giving Lugar additional issues on the right besides his Tea Party problems.

The primary is in early May. The poll was conducted March 12-15 by the Democratic-affiliated Global Strategy Group.

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