US Congress poised to reject Trump’s emergency declaration

Such rejection would pave the way for the first veto showdown under Trump.

The rejection transpired after the fourth Republican, Senator Rand Paul, said he would vote against Trump’s decision.

“I can’t vote to give the president the power to spend money that hasn’t been appropriated by Congress. 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," said the Kentucky senator.

Trump’s insistence to build the wall at any cost has left the GOP in doubt about whether to back Trump in his 2016 campaign pledge or to back down.

“This is not an issue about whether you’re for the wall or you’re against the wall, or whether you like President Trump or you don’t like President Trump, this is an issue about Congress’s constitutional authority to determine spending. It’s Article I,” said Maine Republican Senator Susan Collins.

"Many" other Republican senators "are very uneasy about the precedent that the president's action establishes and who were critical of similar actions that were taken by President Obama," according to Collins.

Tennessee Republican Senator Lamar Alexander asserted that the dangerous precedent must come to an end.

“There is time for the president’s lawyers to take another look and determine whether we can both build the 234 miles of border wall that the president has requested and avoid this dangerous precedent,” Alexander said.

In order to get the funding for his 2016 campaign signature pledge, Trump declared a national emergency at the border in an attempt to circumvent US Congress and get the funding.

Funding for the wall has led to a budget impasse and an ongoing dispute over border security.