Congress's oldest member trails his primary challenger in a new poll released by a group that plans to back his GOP opponent. 

Former U.S. Attorney John RatcliffeJohn Lee RatcliffeKey conservative: Republicans should focus on Sessions, not Rosenstein GOP lawmakers introduce articles of impeachment against Rosenstein Hillicon Valley: Senators working on new Russia sanctions bill | Defense bill includes cyber warfare policy | Hatch tells Google he's still alive | Dem wants tech execs back before Congress | Facebook gets foothold in China MORE leads Rep. Ralph HallRalph Moody HallGOP fights off primary challengers in deep-red Texas Most diverse Congress in history poised to take power Lawmakers pay tribute to Rep. Ralph Hall MORE (R-Texas) by 47 percent-35 percent, according to an automated poll conducted by conservative pollster Wenzel Strategies for Now or Never PAC, which plans to back Ratcliffe.

Hall was forced into a primary runoff earlier this month, winning 45 percent to Ratcliffe's 27 percent. The runoff is in late May.

Republican strategists have been saying for some time that Hall is in real trouble. Ratcliffe, a self-funder, is running a strong campaign and has more money in the bank than the 90-year-old Hall.

Partisan polls should always be taken with a grain of salt. Since neither side has spent much on advertising since the first round of voting, it's unclear what could have driven Ratcliffe to a lead over Hall, unless the pollster is assuming a lower, more conservative turnout in the runoff than what occurred in the primary.

The automated survey of 436 likely Republican primary voters was conducted from March 12-13.