As a true bellwether state, New Hampshire arguably deserves its status as the first in the nation primary state. In the last 36 years, only in 2004 have New Hampshire’s general election voters failed to back the ultimate presidential election winner. What’s more, the margin of victory enjoyed by the winner of the Granite State’s electoral votes often closely mirrors the national vote. New Hampshire’s voters truly have their finger on the political pulse. And that’s why the results of the latest Dartmouth University survey should be a source of concern for Hillary Clinton’s campaign.

Dartmouth pollsters took an early look at the general election landscape and tested some potential head-to-head matchups ahead of 2016. That poll found that, while Clinton continues to enjoy the support of more voters when tested against Sens. Ted Cruz (R-TX) and Rand Paul (R-KY) and Govs. Chris Christie and Mike Huckabee. But that same survey also found Clinton struggling when voters were forced to choose between her and Sen. Marco Rubio (R-FL), and it discovered that the former secretary of state comes up short in a hypothetical matchup against both Govs. Scott Walker and Jeb Bush.

“[I]n the 2014 poll, the Clinton-Bush match-up showed 42.2 percent support for Clinton and 32.3 percent support for Bush. The results of this trial match-up changed significantly in 2015; Bush received 36.9 percent support while Clinton received 34.1 percent support (29.0 percent unsure),” the poll’s release read.

“The Rubio-Clinton trial heat resulted in a virtual tie—34.4 percent for Rubio and 34.5 percent for Clinton, with 31.1 percent unsure,” it continued. “Finally, Walker leads Clinton by a four-point margin, 38.7 percent to 34.8 percent, with 26.5 percent unsure.”

Caveats abound with this survey. There are a huge number of undecided voters, which suggests that this pollster didn’t push its respondents to reveal in which direction they are leaning. That’s a justified decision at this stage of the race. There hasn’t even been one debate yet, much less a primary election, and it would taint this poll’s results to force voters into camps with which they are not familiar. Moreover, this survey did not provide crosstabs, so there is no way to know how the various demographic constituencies voted. Finally, this is a poll of only registered rather than likely voters, and the makeup of the 2016 electorate cannot yet be modeled.

Nevertheless, this poll is interesting and it should represent a big red flag for Team Hillary.