Nebraska's highest court tossed a lawsuit Friday challenging a proposed route for the Keystone XL oil pipeline in a decision that could remove a major roadblock for the $7 billion cross-continental project, which Republicans have vowed to make a key part of their 2015 agenda in Congress. The lawsuit challenged a 2012 state law that allowed the governor to empower Calgary-based TransCanada to force eastern Nebraska landowners to sell their property for the project.