Washington(CNN) Vice President Mike Pence is meeting privately with five Republican senators on Tuesday as the White House continues to ramp up pressure on lawmakers rebuking President Donald Trump over his national emergency declaration on the southern border.
The vice president is expected to sit down with Sens. Thom Tillis, Mike Lee, Rob Portman, Pat Toomey and Lamar Alexander, according to an administration official, as the West Wing is becoming increasingly concerned that the vote will turn into an embarrassing rebuke for Trump.
So far, four Republicans -- Sens. Susan Collins, Lisa Murkowski, Rand Paul and Tillis -- have said they will support the resolution, which amounts to a presidential admonishment. CNN reported last week that the White House has been pressuring Republicans to vote against the resolution, warning those who don't get in line that there could be 2020 election consequences.
Administration officials believe that if only a handful of Republicans support the resolution, it won't be as significant of a problem because some opposition is expected. But if that number grows to 10 Republican senators or more, those officials worry about the optics of the intra-party split.
Speaking Tuesday at the Credit Union National Association's Governmental Affairs Conference, Pence said a vote against the President's emergency declaration is a vote against border security. He called on senators to stand up for border security and stand with Trump.
"Despite the fact that he has clear statutory authority under the National Emergencies Act, some in Congress are actually stopping the President from exercising the authority that Congress gave him to address an undeniable humanitarian crisis on our southern border," Pence said.
The Senate is expected to vote on the resolution of disapproval Thursday, which passed the Democratic-controlled House last month 245-182. Trump has pledged to veto the measure and it's doubtful lawmakers will have enough support to override it.
According to multiple people involved, Lee and Tillis are weighing a proposal that would be considered separately, and later, than this week's disapproval vote and only apply to future declarations. It would require congressional approval for any emergency declaration that lasts longer than 30 days -- rather than the current law, which only allows for congressional disapproval. The change would effectively give more power to Congress when it comes to a President's use of the national emergency power.
The White House counsel has rejected the idea, the people say, and there has been no indication the President would agree to anything that would technically curtail his authority.
That said, it's an effort Lee and Tillis are pushing for as an escape hatch of sorts. There's some sense if the President would agree to support the bill, GOP opposition to the current measure rebuking Trump would significantly drop.
But at this point, they still lack the key element -- presidential support -- as the clock ticks down to the Thursday vote. Several Senate aides say the number of potential "no" votes still sits somewhere between 10 and 15.
White House aides want to avoid another negative news cycle -- one about Republicans breaking with the President -- and don't want lawmakers to see this as an inconsequential vote.
In recent days, White House officials have conveyed a stern message to GOP senators, especially those up for re-election in 2020: There will consequences if they vote with the Democrats and defy the President. They have vowed it will affect their standing with the administration and there will be retribution, including potential primary fights.