Republicans have the edge in two important Senate races in Arkansas and Michigan, according to new polling released Tuesday.

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Most polling has found tight races in both states, though Democrats appear to be in better shape in Michigan since neither Peters nor Cotton are that well known yet statewide.

President Obama isn't in great shape in either state, though his standing in both polls hasn't slipped as bad as he has nationally. His approval rating in Arkansas is at 35 percent with 61 disapproving, just a slight dip from the 37 percent he won in Arkansas last year. In Michigan, his approval rating is at 47 percent, with 51 percent disapproving — that's down from the 54 percent of the vote he won there in 2012.

Pryor's own approval ratings aren't that bad — 44 percent of voters still approve of the job he's doing, with 39 percent disapproving.

Partisan polling should always be taken with a grain of salt — especially when it's released by a group backing one candidate, and Citizens United is a Cotton supporter. But both polls show Democrats are going to have to fight hard to hold control of the Senate. Arkansas is a must-win for the GOP this election cycle, while Michigan is one of a handful of states where they hope to expand the Senate map.

Citizens United's poll of 400 likely voters was conducted by GOP pollster Kellyanne Conway from Dec. 6-7 and has a margin of error of plus or minus 4.9 percent.