Pennsylvania Rep. Tim Murphy holds an overwhelming lead over his GOP primary challenger in the redrawn 18th district, according to an internal Murphy campaign poll obtained by Roll Call.

Murphy led former Senate staffer Evan Feinberg with 74 percent to Feinberg’s 12 percent in the poll conducted by Public Opinion Strategies. Murphy took at least 71 percent of the vote among subsets of voters who identified themselves as “strong” Republican, very conservative, strongly against abortion rights and strong tea party.

The poll of 300 likely GOP primary voters conducted from Jan. 15-16 with a margin of error of 5.7 points, surfaced one day after Sen. Tom Coburn (R-Okla.) endorsed Feinberg, a former Coburn staffer, and labeled Murphy an “Arlen Specter Republican.”

“Tim Murphy is well-positioned to handily win the upcoming GOP primary election,” POS pollsters Neil Newhouse and Robert Blizzard said in a memo. “His very strong image and position on the ballot, coupled with the Republican electorate’s ability to identify Congressman Murphy as a strong conservative make him a very formidable challenge to any potential rival.”

The primary is scheduled for April 24.