Sen. Bill Cassidy, R-La., speaks during a hearing with NIH Director Jay Bhattacharya at the Dirksen Senate Office Building near the U.S. Capitol in Washington, D.C., on February 3. He lost the Republican primary on Saturday. File Photo by Bonnie Cash/UPI | License Photo

May 17 (UPI) -- Sen. Bill Cassidy, a 15-year veteran of the U.S. Congress, lost Louisiana's Republican primary this weekend and appeared to take aim at President Donald Trump in his concession speech.

Cassidy, who has represented Louisiana in the U.S. Senate since 2015, said that though the election didn't turn out the way he wanted, "you don't pout, you don't whine, you don't claim the election was stolen."

"Let me just set the record straight: Our country is not about one individual," he said, NBC reported. "It is about the welfare of all Americans, and it is about our Constitution. And it is the welfare of my people and my state and my country and our Constitution, to which I am loyal.

"And if someone doesn't understand that, and attempts to control others through using the levers of power, they are about serving themselves. They're not about serving us. And that person is not qualified to be a leader."