Senate Democrats say they are poised to overcome a Republican filibuster of the looming vote on gun control. On Tuesday, a number of Republicans said they would not block consideration of a gun-control package, prompting Senate Majority Leader Harry Reid to announce a vote for Thursday. But even if the legislation is allowed to advance, its key components face opposition not just from Republicans, but Democrats in conservative states. The bill already excludes an assault weapons ban after Democrats found it had insufficient support, though it may still come up as an amendment. Democratic Sen. Joe Manchin of West Virginia and Republican Sen. Patrick Toomey of Pennsylvania are expected to announce a compromise that would water down one of the bill’s remaining provisions, expanding background checks. The Manchin-Toomey amendment would exclude more gun buyers from the bill’s proposed expansion of background checks, leaving out sales between family members and other transfers.