The White House, in an apparent push to get Republicans on board, has increased efforts to brief lawmakers about its legal rationale for boat strikes in the Caribbean. Several Republican senators are voicing uncertainty ahead of a vote to block the Trump administration from taking military action against Venezuela, setting up a potential rebuke of the president over the scope of his war powers. The White House, in an apparent push to get Republicans on board, has started sharing more information with Congress about its rationale for strikes on suspected drug smugglers in the Caribbean Sea. Secretary of State Marco Rubio will brief lawmakers on Wednesday as senators weigh the bipartisan legislation. Four Senate Republicans said Wednesday they are still reviewing the Justice Department’s legal rationale, which Congress received last week, and two others have already voted against the military strikes. It would only take three more GOP defections to flip the outcome of the upcoming vote. “I want to make sure that we do our due diligence and that we’re doing things correctly long-term,” said Sen. Mike Rounds, (R-S.D.), a member of the Intelligence and Armed Services panels, who notedthe stepped-up engagement from administration officials. Democratic lawmakers have objected to the U.S. military strikes on vessels in the Caribbean and eastern Pacific that have killed more than 60 people. Rubio’s push to shore up support on Capitol Hill — where he’ll meet with congressional leaders and national security committee heads from both parties — comes amid bipartisan frustration that the Trump administration has left Congress in the dark about its increasingly aggressive military campaign. “I’m still looking at everything,” said Sen. Todd Young (R-Ind.), a Senate Intelligence Committee member. “I’m doing my homework.” Lawmakers are particularly interested in the intelligence behind the strikes and the Justice Department’s legal justification for them. “I need to read the legal opinion that the Office of Legal Counsel did,” said Sen. Susan Collins (R-Maine), who chairs the Appropriations Committee. “I’ve gone to the classified briefing, as I said, but I’d like to read that opinion.” Sen. Jerry Moran (R-Kan.) said he wants clarity on when the Constitution requires Congress to authorize military force. “I’m trying to figure out where that line is drawn,” he said, adding that he also wants answers to “factual” questions. “What are we doing and what is yet to come?” The last war powers measure failed 48-51 with Sens. Lisa Murkowski (R-Alaska) and Rand Paul (R-Ky.) crossing the aisle to support it. Both indicated on Wednesday that they have not changed their minds. Paul said there have been “rumblings” of more dissatisfied Republicans switching sides amid concerns about the lack of legal clarity. “Really killing people without an accusation, without evidence and without a trial is not something that I find acceptable,” he said. A bipartisan group of defense lawmakers pressed President Donald Trump directly for more details in a letter sent to the White House on Tuesday, arguing efforts to stem the flow of narcotics into the U.S. “must be done within the legal, moral, and ethical framework that sets us apart from our adversaries.” The letter was signed by Republican Reps. Don Bacon of Nebraska and Mike Turner of Ohio as well as Democrats Jason Crow of Colorado and Seth Moulton of Massachusetts, all senior members of the House Armed Services Committee. “The administration should come to Congress, make the legal case, present their intelligence, and assure the American people that any military action is grounded in both authority and accountability,” Bacon said in a statement. “If those standards are met, I’m confident Congress and the American people will stand behind decisive action to confront this crisis.” Lead Art: Sen. Mike Rounds (R-S.D.) and several other Republicans said they are still reviewing the administration's justification for U.S. military strikes in the Caribbean. | Francis Chung/AP