"It is dangerous when presidents write their own laws, impose their own taxes, spend money how they want and Congress looks the other way," Andrew Napolitano, Fox News' senior judicial analyst, said.
Money originally intended for the Airborne Warning and Control System and funding for U.S. allies has also been redirected to the southern border wall.
"It's a waste of money," one social media user said in response to the U.S. Customs and Border Protection agency's request for public comment.
Confusion over where the U.S.-Mexico border begins and ends led to Mexican soldiers temporarily detaining U.S. soldiers who believed they were in Mexican territory when they were in U.S. territory.
Defense Department documents obtained by Newsweek show a troop surge at the southwest border, a request made by the White House amid President Donald Trump's renewed push to stem the flow of undocumented immigrants.
There is a group, a family that has a United Methodist Church, they are preachers, they are the ones that started the sanctuary city. They are directly getting money from George Soros and others," Beck said.
"We're going to court to ensure that President Trump's desperate bid to fund his border wall with a bogus national emergency and taxpayer money fails," an ACLU staff attorney said.
"This is a fake emergency! Donald Trump is lying about the border in order to build his monument to racism," Omar tweeted on Wednesday.
Nielsen told Fox News' Tucker Carlson that every option was on the table to stop illegal immigration into the U.S.
Late-night TV host suggested that students planning to vacation in Cancun this year could spend spring break at Trump's wall instead.
Lawmakers in Alabama are pushing to give taxpayers the option to donate a portion or all of their state income tax return to the president's cause.
CNN conservative political commentators Ben Ferguson and Tara Setmayer's discussion on President Donald Trump's national emergency declaration quickly descended into an incoherent yelling match.
"They will vote to surrender military spending projects in their own home states and districts to avoid displeasing him," Washington Post columnist Dana Milbank wrote.
"Congress gave these legislative powers away in 1976, and it is far past time that we as an institution took them back," said Senator Mike Lee, a Utah Republican.
"His personality is almost the opposite of 'authoritarian,'" Coulter said of Trump.
"It doesn't make a s**t of difference who is in office," Sheriff Arvin West of Texas's Hudspeth County said. "They're not going to listen to us. They don't care to listen to us."
"Billions of dollars for a border wall is a waste of money," Senator Kamala Harris, a California Democrat and presidential candidate, said.
"What we should be doing is focusing on technology, manpower and physical barriers where it makes sense," said Republican Congressman Will Hurd from Texas.
"They're people coming up here for economic purposes. I don't blame them for that," John Kelly said.
"The entire premise of a wall is not based in fact," Alexandria Ocasio-Cortez said.
House Speaker Nancy Pelosi said Democrats will fight President Donald Trump in Congress, the courts and the court of public opinion over his national emergency declaration for a border wall.
"There is simply not ample evidence to support the president's contention of a national security crisis at our southwestern border," Wisconsin Governor Tony Evers said.