TransCanada Corp should push ahead with an $8 billion Keystone XL pipeline expansion after the state of Nebraska on Monday approved a route that would raise the cost of the controversial project, some shareholders said. The approval quashed the last regulatory hurdle for the nearly decade-old project, but the Nebraska Public Service Commission denied TransCanada’s preferred route. That opened the door to potential delays and emboldened activists who said they would try to kill the project through protests. TransCanada has so far spent $3 billion on the 1,179-mile pipeline and has said it would make a final investment decision by December, based on commercial support and Nebraska’s regulatory approval. More clarity on the company’s strategy is expected at its investors day next Tuesday. […]