Sen. Carl Levin (D-Mich.) is in strong shape for reelection if he decides to run for a seventh term, according to a new survey from the Democratic-leaning Public Policy Polling.

The senator leads a number of possible GOP opponents by between 18 and 22 percentage points and cracks the 50 percent threshold in every possible matchup. His closest possible challenger in the poll is Rep. Candice Miller (R-Mich.), who trails by 52 to 34 percent.

Levin, who will be 80 years old by his next election, hasn't said whether he's running again. Even if he does retire the seat may not be a top GOP target: Michigan has leaned Democratic and Republicans have a number of red-state seats to aim for in 2014 including Alaska, Arkansas, Louisiana, South Dakota and West Virginia.

The poll of 650 registered voters was conducted from Dec. 13-16 and has a margin of error of plus or minus 3.8 percent.