Mitt Romney has broken through a key ceiling of support in the latest Gallup national GOP presidential poll.

Romney is the first candidate to hit the 40 percent mark in the poll, and now holds a 14 percent lead over Rick Santorum, who came in at 26 percent, followed by Newt Gingrich at 14 percent and Ron Paul at 8 percent.

On five previous occasions, candidates have tested the upper 30 percent range, only to fall back with the rest of the pack shortly after. Romney has tested that upper boundary three times, while Gingrich and Santorum have each been turned back once.