After President Obama’s combative State of the Union address on Tuesday, the level of Republican backlash was expected, but now he is taking unexpected flak from members of his own party – and they could prove to derail any of his goals for the remainder of his presidency.

Some Democrats spent Wednesday tearing the president’s agenda to pieces. Those in the Senate could prove to be a particular problem for the president because if they defect, they could help provide the numbers the Republicans would need to pass important legislation – possibly overriding the presidential veto Obama continued to threaten us with on Tuesday evening.

Key Democrats want Obama to slow diplomatic talks with both Cuba and Iran, they were not pleased with his push for new free-trade deals, and it is likely that Democrats in the Senate will play a key role in advancing legislation approving the Keystone XL pipeline.

On Wednesday, Senator Bob Menendez, D-N.J., sent a letter to Secretary of State John Kerry, writing some of the toughest Democratic criticism aimed at the president’s foreign policy. Menendez, a Cuban-American and the top Democrat on the Senate Foreign Relations Committee, warned Kerry about the Castro regime.

“Mr. Secretary, after five decades of authoritarian, one-party rule, we must recognize that the Castros will never relax their iron-fisted control over Cuba unless compelled to do so,” Menendez wrote. “As the Administration pursues further engagement with Cuba, I urge you to link the pace of changes in U.S. policy to reciprocal action from the Castro regime.”