Republican senator, Trump critic Corker won't seek re-election

US Senator Bob Corker, a senior Republican who has been critical of Donald Trump's presidency, has announced he will not seek re-election next year, opening the door for a potentially more conservative successor.
"After much thought, consideration and family discussion over the past year, Elizabeth and I have decided that I will leave the United States Senate when my term expires at the end of 2018," Corker said in a statement.
Corker said he believes that "the most important public service I have to offer our country could well occur over the next 15 months, and I want to be able to do that as thoughtfully and independently as I did the first 10 years and nine months of my Senate career."

The 65-year-old from the state of Tennessee is chairman of the Senate Foreign Relations Committee, and has been a reliably bipartisan voice in that powerful role.
But he also found himself in the spotlight in August when he provided blunt criticism of the president in the aftermath of race-related violence in Charlottesville, Virginia.
Trump, Corker had said, "has not yet been able to demonstrate the stability, nor some of the competence, that he needs to demonstrate in order to be successful."

The scathing remark drew the ire of Trump on Twitter, who said the senator had been "constantly asking me whether or not he should run in '18. Tennessee not happy!"

For months, conservatives are said to have sought a strong primary challenger to run against Corker next year. Among the names mentioned is Mark Green, a state senator who had been a Trump choice for US Army secretary.
Green withdrew from consideration for that post amid a backlash over his past controversial statements on gay rights issues, Islam and evolution.