Election Day is quickly approaching, and with it comes endless political analysis, predicting, modeling, and polling. For those who have been following the polls for weeks and months, it seemed like New Jersey’s Senate race would not be much of a contest. Now, the polls are putting Democratic Senator Bob Menendez and his opponent, Republican pharmaceutical executive Bob Hugin, closer than ever.

Inside Elections, one political analysis publication, has characterized New Jersey as “Likely Democratic” for this year’s Senate race; this has remained so throughout the election cycle. But most recently, the Cook Political Report has put New Jersey’s election into the “Toss Up” category. This report, and many other news reports, attribute Hugin’s surge to political advertising. According to the most recent FEC report, Hugin has spent $27.7 million, while Menendez spent $11.8 million. SuperPACs are pouring in millions for both candidates.

Hugin’s millions are largely being spent on political ads that focus on Menendez’s corruption charges and ethics issues. Although his trial ended in a mistrial and thus he was not convicted, the negative perception remains. Perhaps the frequency with which voters are seeing these ads is having an effect. Pundits point out that the recent shift in the polls is not so much voter desire to see Hugin elected but rather a wish to not have Menendez remain in office. These analysts point to the June Democratic primary, where an unknown challenger garnered 38% of the vote. While Menendez’s victory was decisive, the margin was actually smaller than expected.

RealClear Politics, which analyzes results of different polls, puts Menendez up 7.7 points. In the varied polls, Menendez’s lead ranges from 5 to 10 points. More polls are coming soon, so this may change—in either direction, of course. With a little over a week to the midterm elections, it should be an interesting ride.