Republican Sen. Rand Paul of Kentucky says he will support legislation to reverse President Trump's declaration of a national emergency along the southern border, setting the stage for the first veto of the Trump presidency.

In a FoxNews.com opinion piece, Paul says, "I support President Trump. I supported his fight to get funding for the wall from Republicans and Democrats alike, and I share his view that we need more and better border security. However, I cannot support the use of emergency powers to get more funding, so I will be voting to disapprove of his declaration when it comes before the Senate."

Paul adds, "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."

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According to the Bowling Green Daily News, Paul said he couldn't vote to give Mr. Trump the "power to spend money that hasn't been appropriated by Congress" during remarks at the Southern Kentucky Lincoln Day Dinner on Saturday.

"We may want more money for border security, but Congress didn't authorize it. If we take away those checks and balances, it's a dangerous thing," Paul suggested, according to the paper.

Mr. Trump issued his emergency declaration as a way to free up funding to build his long-promised wall along the southern border after Congress refused to provide the $5 billion he requested.

Paul's vote in favor of the resolution blocking Mr. Trump's order would give opponents the simple majority needed for it to pass the upper chamber. The House passed its version of the resolution last week, largely along party lines, and the Senate must hold a vote within two weeks.

Paul joins three other Republican senators in supporting the effort to stop the order: Lisa Murkowski of Alaska, Susan Collins of Maine and Thom Tillis of North Carolina. Mr. Trump vowed to veto the resolution "100 percent."

Tillis, in an op-ed for the Washington Post last week, echoed Paul's criticism of the order: "As a U.S. senator, I cannot justify providing the executive with more ways to bypass Congress."

"As a conservative, I cannot endorse a precedent that I know future left-wing presidents will exploit to advance radical policies that will erode economic and individual freedoms," Tillis wrote.