Trump plans to use emergency powers to secure $3.6 billion from the Department of Defense's military construction funds to build his proposed border wall. He will take executive actions to divert another roughly $3 billion toward the project, along with $1.4 billion allotted by Congress last month. Trump declared a national emergency after Congress did not approve the $5.7 billion he wanted for border barriers.

Sen. Rand Paul, R-Ky., announced late Sunday that he would support a measure to terminate the flex of executive power, joining three of his Republican colleagues. The GOP-controlled Senate plans to take up the proposal, which the Democratic-held House already passed, by mid-March. If all 47 Senate Democrats support the measure as expected, four Republicans add up to the simple majority needed to approve it.

A fourth Republican senator plans to vote to block President Donald Trump's national emergency declaration, giving the chamber enough support to reject the president's action barring any changes.

Despite the Senate's support for the resolution, Congress likely will not block the emergency declaration. Trump has pledged to veto it. If he rejects the bill, the House and Senate would have a difficult time finding two-thirds majorities to override the veto.

Paul joins GOP Sens. Susan Collins of Maine, Lisa Murkowski of Alaska and Thom Tillis of North Carolina in pledging to vote to terminate the declaration. Others such as Sen. Lamar Alexander, R-Tenn., have signaled they could join that group if Trump does not change course.

In a Fox News column, Paul wrote that he backs Trump's effort to put money toward a border wall. But he wrote that he "cannot support the use of emergency powers to get more funding."

"Every single Republican I know decried President Obama's use of executive power to legislate. We were right then. But the only way to be an honest officeholder is to stand up for the same principles no matter who is in power," Paul wrote.

Senate Majority Leader Mitch McConnell, R-Ky., and House Minority Leader Kevin McCarthy, R-Calif., have both supported Trump's emergency declaration. McConnell acknowledged Monday that the Senate will pass the resolution disapproving it, but stressed that Congress likely will not be able to overcome Trump's veto, according to CBS News reporter Mark Knoller.

Mark Knoller McConnell tweet

In passing the measure to block the emergency declaration, the Democratic-held House fell well short of a veto-proof majority. While 245 House members voted for the resolution, 290 would need to back it to overcome a veto. Democrats currently control 235 seats, while Republicans hold 197 and three are vacant.

Meanwhile, 67 senators would have to support it to reach the two-thirds threshold needed to circumvent Trump.

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