The new agriculture bill will almost surely fail to pass.
Conclusion
The new agriculture bill will almost surely fail to pass.
Evidence
The leaders of all major parties have stated that they oppose it.
Evaluate
If we were being asked for an assumption or a principle underlying the argument, we'd articulate this If Premise, Then Conclusion linking idea:
If ... Then ... leaders of all major new agric parties have said they bill probably oppose new agric bill won't pass
Since this is Strengthen, though, the answers are usually more conversational than mathematical.
Goal
Let's look for something that strengthens the link between "leaders of all major parties oppose it" and "bill won't pass", or any answer that says something else that increases the plausibility that the new bill won't pass.