WASHINGTON (CNN) -- Every American taxpayer would get a $100 rebate check to offset the pain of higher pump prices for gasoline, under an amendment Senate Republicans hope to bring to a vote Thursday. However, the GOP energy package may face tough sledding because it also includes a controversial proposal to open part of the Arctic National Wildlife Refuge in Alaska to oil exploration, which most Democrats and some moderate Republicans oppose. Democrats are also expected to offer their own competing proposal, as members of both parties jockey for political position on the gas price issue. The energy package, sponsored...