Robert F. Kennedy Jr. denied Friday that he planned to end his presidential campaign and throw his support behind Donald Trump. The independent candidate’s modest poll numbers have collapsed since President Joe Biden ended his campaign and endorsed Vice President Kamala Harris, and he reportedly had talks earlier this month about taking a possible position in a second Trump administration, but Kennedy insisted Friday he would remain in the race. “Fake news,” he posted on X in response to a report that he had canceled campaign events and has discussed dropping out to possibly endorse Trump. Wan…