Coercion infringes freedom of thought and liberties to act freely, in this case, the Senate liberty to execute a constitutional right.
Although none specific right protecting this freedom of thought in constitution, which there should be, I'd assume this type of coercion compromises Article 1 Section 2.7 and Article 2 Section 1.1 which should mean the Senate has the "democratic" freedom of functioning without being overstepped by coercive pressure, specially since in Article 3 Section 1.5 says nothing of coercing the Senate to change their vote.
If it can be coerced not to-
enact, amend, or repeal laws by a majority vote
-freely then there is no procedural need for the laws to be passed in the Senate, and they'd instead have the Delegate's opinion first and then the Senate would agree or not agree. It's a procedural error, overstepping, in practical terms, and politically it cuts democracy if you have limited choices because the Delegate has an opinion.
Follow what the constitution says, nothing there saying Delegate has the right to coerce the Senate before it may enact, amend or repeal laws by a coercive vote.
In more practical words "Ya doin'it wrong!", it's politically incorrect and incorrect process of powers.
PS: Adding wiki about
Coercion. Also, it'll be the Court's decision to say this is actual coercion or not, I defend so and "We" would like the Senate to see the seriousness of this issue, either way "We" would like to see legislation that ensures the liberties of the Senate won't be disturbed again.