WASHINGTON — Sen. Kirsten Gillibrand is expected to move toward launching a 2020 presidential campaign within days by forming an exploratory committee, according to several people familiar with her plans. The New York Democrat will likely announce her intentions ahead of a trip to Iowa this weekend, one person said. She will be a guest Tuesday night on CBS’ “The Late Show with Stephen Colbert.” The people spoke to The Associated Press on condition of anonymity because they weren’t authorized to speak on Gillibrand’s timing.