As forces in both major parties have begun to mobilize against a Trump presidency, a new national poll out Tuesday reveals the most surefire way to derail the GOP frontrunner: Nominate Bernie Sanders.

The NBC News/SurveyMonkey Weekly Election Tracking Poll found that if the 2016 presidential election were held today, 53 to 40 percent of voters would elect Sanders over Donald Trump—which is more than double the margin that Hillary Clinton holds over the presumptive Republican nominee.

According to the survey, which was conducted online from May 2 through May 8, the former secretary of state also leads Trump, but with a far smaller margin: 49 to 44 percent, with an error estimate of plus or minus 1.3 percentage points.

Meanwhile, a separate poll found that in key presidential swing states the anointed nominees are running neck and neck.

The latest Quinnipiac University survey released Tuesday shows Clinton beating Trump by just one point—43 to 42 percent—in both Florida and Pennsylvania. In Ohio, the real estate mogul holds a four-point lead over Clinton, with 43 to 39 percent.

Echoing the NBC News findings, Sanders bests Trump in all three of those states’ hypothetical match-ups. The Vermont senator leads by two percentage points in both Florida and Ohio (44-42 percent and 43-41 percent, respectively) while beating Trump 47 to 41 percent in Pennsylvania.

The Quinnipiac survey notes that “since 1960 no candidate has won the presidential race without taking at least two of these three states.”