Republican Sen. Mitch McConnell, of Kentucky, is announcing on Thursday that he won’t seek reelection next year.It ends a decadeslong tenure as a power broker who championed conservative causes, but ultimately ceded ground to the fierce GOP populism of President Donald Trump.McConnell, the longest-serving Senate party leader in U.S. history, chose his 83rd birthday to share his decision not to run for another term in Kentucky and to retire when his current term ends. He informed The Associated Press of his decision before he was set to address colleagues in a speech on the Senate floor.“Seven times, my fellow Kentuckians have sent me to the Senate,” McConnell said in prepared remarks provided in advance to the AP. “Every day in between I’ve been humbled by the trust they’ve placed in me to do their business here. Representing our commonwealth has been the honor of a lifetime. I will not seek this honor an eighth time. My current term in the Senate will be my last.” Watch his full remarks here:McConnell, first elected in 1984, intends to serve the remainder of his term ending in January 2027.he Kentuckian has dealt with a series of medical episodes in recent years, including injuries sustained from falls and times when his face briefly froze while he was speaking.In Kentucky, McConnell’s departure will mark the loss of a powerful advocate and will set off a competitive GOP primary next year for what will now be an open Senate seat.One of his proteges and former Kentucky politician Daniel Cameron announced he'd be running just minutes after McConnell went on the Senate floor.Congressman Andy Barr said Thursday he's considering running."Kentucky deserves a Senator who will fight for President Trump and the America First Agenda," he posted.McConnell and Trump were partners during Trump’s first term, but the relationship was severed after McConnell blamed Trump for “disgraceful” acts in the Jan. 6, 2021, Capitol attack by his supporters. A momentary thaw in 2024 when McConnell endorsed Trump didn’t last.Last week, Trump referred to McConnell as a “very bitter guy” after McConnell, who battled polio as a child, opposed vaccine skeptic Robert F. Kennedy Jr.’s confirmation as the nation’s top health official.