A new poll shows Sen. Thad CochranThad CochranOvernight Finance: GOP offers measure to repeal arbitration rule | Feds fine Exxon M for Russian sanctions violations | Senate panel sticks with 2017 funding levels for budget | Trump tax nominee advances | Trump unveils first reg agenda Senate committee ignores Trump, House budgets in favor of 2017 funding levels Overnight Finance: CBO finds 22M more uninsured under Senate health bill | GOP agrees ObamaCare taxes must go | Supreme Court to look at Dodd-Frank whistleblower protections | More tax reform hearings | Green light for partial travel ban | MORE (R-Miss.) vulnerable to a primary challenge if he decides to run for reelection next year.

The survey, from Democratic firm Public Policy Polling, gives him just a 6-point lead over his only announced primary opponent, state Sen. Chris McDaniel. Cochran takes 44 percent support to McDaniel's 38 percent support among GOP primary voters.

And voters are split on how they feel about Cochran, with 45 percent approving of his job performance, while 42 percent disapprove. Fifty-five percent of respondents say they would like the GOP candidate for Senate next year to be more conservative than Cochran.

Cochran hasn't yet announced his decision on running, but is expected to do so at the end of this month.

If he does decide against it, a wide range of Republicans are expected to enter the race. McDaniel takes a slight lead in a seven-person field, with a quarter of the votes. Close behind him is Secretary of State Delbert Hosemann, who takes 23 percent support.

The survey was conducted among 422 GOP primary voters from Nov. 15-17.