Sen. Ben Nelson (D-Neb.) has taken a major hit in public opinion as a direct result of his support for health care reform legislation, a new Omaha World-Herald poll found.

According to the statewide survey of 500 registered Nebraska voters in his overwhelmingly Republican home state released on Sunday, Nelson’s job approval rating has sunk to 42 percent, with 48 percent disapproving. That stood in stark contrast to Sen. Mike Johanns’ (R-Neb.) 63 percent approval rating; Johanns has consistently opposed the Democrats’ health care agenda.

Overall, 60 percent of Nebraskans oppose the health care reform bills that passed the House and Senate late last year. The poll found that voters’ attitudes regarding Nelson’s support for the Senate bill broke along party lines, with three-quarters of Republicans opposing his vote, while only 22 percent of Democrats felt similarly.

The poll was conducted Jan. 8-12 by Omaha-based Wiese Research Associates and has an error margin of 4.4 points. The survey data was obtained via telephone interviews.

Despite being a Democrat in a conservative state, Nelson has generally enjoyed high approval ratings, first during two terms as governor and then for most of his eight years in the Senate. He won re-election with 64 percent of the vote in 2006, and in a poll conducted in April of that year commanded a 73 percent job approval rating.

But Nelson has come under fire not just for his vote, but for the impression that he was the crucial 60th vote that made it possible for the health care bill to overcome a GOP filibuster and clear the Senate. Nelson has also taken heat at home for inserting a special, $100 million provision into the legislation to cover Nebraska’s cost of a proposed Medicaid expansion.

Nelson on Friday asked that the controversial measure, dubbed the “Cornhusker Kickback— by critics, be removed from the bill and replaced with one that treated all states equally.

The Senator blamed the drop in his approval ratings on millions of dollars in “misleading advertisements— that have mischaracterized the Democrats’ health care reform bill.

“I believe that, over time, as the special interest ads subside, Nebraskans will understand the bill I support will improve their health care, because it ends the denial of coverage due to pre-existing conditions, it reduces spiraling costs and it provides new access to coverage for 220,000 Nebraskans without health care today,— Nelson told the World-Herald in a prepared statement.