GRANTS PASS, Ore. (AP) — Two years ago, U.S. Rep. Peter DeFazio weathered a surprisingly strong challenge from tea party favorite Art Robinson, an independent research scientist in molecular biology, sheep farmer and producer of a home schooling curriculum who got major support from a New York hedge fund manager.

Robinson is challenging DeFazio again this year, and is considered unlikely to do any better than his 11-point loss in 2010. The super PAC contributions from Renaissance Technologies CEO Robert Mercer, which have financed independent attack ads against DeFazio, are less than half the $650,000 donated in 2010. Mercer is also a major contributor to Robinson’s research lab. The Register-Guard newspaper has reported tax records show from 2005 to 2010 the Mercer Foundation made annual donations totaling $360,000 to Robinson’s nonprofit Oregon Institute for Science and Medicine.