Former Alabama state Supreme Court Chief Justice Roy Moore holds a narrow lead over incumbent Sen. Luther Strange Luther Johnson StrangeSessions hits back at Trump days ahead of Alabama Senate runoff The biggest political upsets of the decade State 'certificate of need' laws need to go MORE (R-Ala.), as the two jockey in the final weeks before Alabama's special GOP Senate primary runoff, according to a new poll.

The poll from Harper Polling puts Moore at 47 percent to Strange's 45 percent, with 8 percent of voters undecided. The poll also found that more voters consider Strange, who was endorsed by President Trump, as the candidate most supportive of the president by a margin of 10 points.

The data are similar to recent polling figures released by the Senate Leadership Fund, the Senate leadership's allied super PAC, which found Moore up by just 4 points. But those two surveys are a far cry from others released last week that showed Moore up by a double-digit margin, a discrepancy that underscores how difficult it is to measure a race that's expected to have low turnout.