No one else is above 5%, and it is strange how all four candidates end up on round numbers. The odds of that are pretty low, about 1-1024. Also, with a 19.0% lead, that means Clinton has reached the firewall point in New Hampshire, where even in the event that she finishes third in Iowa, she would still (narrowly) be projected to win in New Hampshire. That makes this poll a very big moment for the Clinton campaign, as it is actually the first time since February where she is clearly in the driver's seat for the nomination. For a very long time, she was still vulnerable to a second or third place finish in Iowa, while simultaneously trailing in the Iowa polling average.
In the Senate race, Jean Shaheen leads John Sununu in two new polls, but not by the double digit margins that previous polls had shown:
Rasmussen. 9/16. Likely voters. MoE 4.5% (No trend lines)
It should be noted that the incumbent rule does not, and has never, applied in campaigns where the challenger previously held equivalent elected office (Shaheen was once Governor of New Hampshire). This was even noted in the original paper proposing the incumbent rule theory. So, this does in fact look like a reasonably close race, given that two polls confirm the closer campaign at the same time.