A new National Republican Senatorial Committee ad will reprise a familiar attack on Democratic Sen. Mark Pryor, charging that he is too much in line with President Obama's policies for Arkansas voters to accept.

The Web video, which mimics the tone and aesthetic of a nature documentary, criticizes Pryor, D-Ark., for his votes in support of Obamacare and to increase the debt limit.

“In the open, he tries to camouflage himself as a moderate, sometimes even tactfully hiding amongst the conservative species,” a narrator says in the ad. “But, when no one’s looking, his true colors are revealed in their glory, exposing the dangerous truth.”

Tying Pryor to Obama, who remains unpopular in the solid red Arkansas, has been the focus of Republican efforts over the past several weeks. In addition to the new ad, the group created a website, "Mark Pryor: Obama Comes First."

Pryor campaign manager Jeff Weaver has accused the Republican committee of relying on "recycled misinformation."

Pryor is widely considered to be among the most vulnerable Democratic incumbents in the Senate. He faces what is expected to be a tough challenge from Republican Rep. Tom Cotton, who is already benefiting from the backing of major party donors inside and outside Arkansas.