Donald Trump Jr. does not think his dad Donald Trump’s campaign is a sinking ship. The former First Son of the United States and his fiancée, Kimberly Guilfoyle, showed support for the ex-president during a Trump boat rally held in Jupiter, Fla., over the weekend. In a video shared to X (formerly named Twitter), Trump Jr., 46, and his future wife, 55, stood at the edge of a dock while waving to a group of boats with Trump 2024 flags passing by. Trump Jr. and Guilfoyle appeared in good spirits, as they seemed supportive toward several of the boats propping up an upside-down American flag. The s…