LINCOLN, Neb. (AP) – Activists from California, Texas and Nebraska have converged in Lincoln to present their case against a proposed tar sands oil pipeline.  Approximately 40 people gathered Wednesday for a discussion of the Keystone XL pipeline, which is designed to carry oil from Canada to Gulf Coast refineries. Several activists were on their way to an ongoing White House protest against the pipeline, or had just come from it after being arrested. Environmental groups have raised concerns that the pipeline could foul underground and surface water supplies, increase air pollution around refineries and harm wildlife. Pipeline supporters say it is safe and will create much-needed jobs. David Daniel, an east Texas landowner, says he was repeatedly pressured into signing a portion of his property away with legal threats.