Opponents of Obama initiatives threaten to curtail funding as 2016 presidential aspirants stake out their embargo positions Congressional critics of Barack Obama’s deal to end US isolation of Cuba are threatening to frustrate key elements of his plan by withholding funding for a new embassy and blocking the appointment of an American ambassador to Havana.Democratic senator Bob Menendez, a leading US critic of the Castro regime and outgoing chair of the Senate foreign relations committee, also insisted there was little chance that Congress would agree to a formal repeal of the legislation behind the current trade embargo.