When President Obama traveled to North Carolina on Wednesday to speak about manufacturing, one notable Democrat was absent: Sen. Kay Hagan, who opted instead to stay in Washington, where the Senate was in session but not voting.

There might have been more at play than Hagan's work schedule. The first-term senator also faces a tough re-election bid this fall in a state that has become less welcoming to Democrats, and where campaign appearances with the president are of diminishing value.

The president has lately maintained a high profile at fundraising events for the Democratic Party's campaign arms — in no small part because the outcome of Senate races this fall will determine whether he will face a Republican Congress during his final two years in office.

But, with his approval ratings historically low, Obama's presence has not so far been as welcome on the campaign trail.

Last year, Sen. Mary Landrieu, D-La., gave Obama the cold shoulder when he traveled to her home state to speak about the economy — although she had previously said she would be "proud to be with him" were he to visit. Landrieu is among the most vulnerable Democratic senators up for re-election this year.

Now, Hagan has taken a similar tack — just as new poll numbers reaffirmed the political slog she faces.

A survey released Tuesday by Public Policy Polling, a Democratic-leaning firm, showed Hagan with a 49 percent disapproval rating, and in a dead heat with every one of her potential Republican challengers.

And, in a potentially troubling sign for Hagan, more than half of people surveyed viewed the implementation of Obamacare as unsuccessful.