A 13-point shift in public opinion over the past two months gives Republicans an edge over Democrats heading into the 2014 midterm elections, according to a new poll -- and the advantage for the GOP appears to be widening.

The CNN/ORC International survey showed 49 percent support for a generic Republican, compared with 44 percent for a Democrat. That's a better result for Republicans than last month, when the same share of people picked Republicans but 47 percent favored Democrats.

The new poll shows a dramatic shift from two months ago, when 50 percent of people supported Democrats, compared with 42 percent who chose Republicans.

The Republican Party, though predicted by most to retain control of the House of Representatives, still faces a tough slog to take back the majority in the Senate. Republican candidates would likely need to unseat at least three Democratic incumbents, as well as win three open-seat races in which they are currently favored.

But the outlook for Republicans appears perhaps rosier than ever, with support for the party boosted in no small part by lingering problems with and questions about President Obama's signature health care law. The White House and Democrats have tried to project flexibility as they have proposed and implemented fixes to Obamacare and the healthcare.gov insurance marketplace, but public perception of the law remains negative in most polls.