U.S. Senator Bob Corker meets with the Times Free Press editorial board for the final time as a sitting senator in the newsroom on Monday, Nov. 19, 2018 in Chattanooga, Tenn.

NASHVILLE — After criticizing President Donald Trump earlier Sunday on a national news show, retiring Republican U.S. Sen. Bob Corker resumed an 18-month feud after he was slammed by the president on Twitter.

Speaking on CNN's "State of the Union," Corker, a Chattanoogan, said a partial government shutdown that began over the weekend was avoidable. He added that Trump could have gotten $25 billion for border security "just by dealing with the Dreamers," the issue over the legal status of undocumented student and immigrants who were brought to the U.S. as children.

"This is a made-up fight so the president can look like he's fighting," said Corker, the chairman of the Senate Foreign Relations Committee who departs Congress on Jan. 3.

Calling the situation a "purposely contrived fight," Corker said the United States' borders will be unsecured "no matter who wins the shutdown fight" and further characterized the entire situation as "juvenile."

"It's not just about the money, it's what we are spending it on," Corker told host Jake Tapper, pointing to security technology developed by the U.S. in Afghanistan and Iraq. He said the irony is that the fight prompting the shutdown amounts to maybe $2 billion.

Corker also criticized the president over his abrupt decision to yank U.S. troops out of Syria and at least some out of Afghanistan.

"ISIS is now concentrated in the Euphrates River Valley," Corker said. "We're just a few months away from finishing something that we started where we would annihilate a large number of ISIS members. And we stopped.

"I'm just saddened for our country," he added. "I'm saddened for the broken relationships with countries that have been with us." And he warned that many Kurds and others who worked with the U.S. "likely will be killed and slaughtered by either the Syrians or the Turks."

The senator also lamented the newest administration departure of Defense Secretary James Mattis as well as the recent departure of Chief of Staff John Kelly and this year's earlier exit of Secretary of State Rex Tillerson, who was recently critical of the president.

Later Sunday, Trump fired back at Corker via Twitter.

"Senator Bob Corker just stated that, "I'm so priveledged [sic] to serve in the Senate for twelve years, and that's what I told the people of our state that's what I'd do, serve for two terms." But that is Not True - wanted to run but poll numbers TANKED when I wouldn't endorse him..," Trump tweeted.

In turn, Corker retweeted the president: "Yes, just like Mexico is paying for the wall," a reference to Trump's repeated assertions Mexico would pay for the border wall.

Corker also smacked back with the hashtag "#AlertTheDaycareStaff."

That's a reference to a Corker jab at Trump in October 2017 after the two attacked each other in a blistering Twitter exchange that began when Trump accused Corker of "not having the guts" to run for re-election.

In response, Corker tweeted: "It's a shame the White House has become an adult day care center. Someone obviously missed their shift this morning."

Trump also contended in the same 2017 exchange that Corker had "begged" him for an endorsement for re-election. "He also wanted to be secretary of state, I said 'NO THANKS,'" Trump tweeted. "He is also largely responsible for the horrendous Iran deal!"

Contact staff writer Andy Sher at or 615-255-0550. Follow on Twitter @AndySher1.