system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why are Republicans in the US congress so opposed to Obama's decision to hold nuclear talks with Iran?
gpt
They're not at all opposed to the talks.

What they want is for the result of the talks to be submitted to the Senate for ratification like any other treaty.  The Administration wants to conclude an "agreement" that isn't a treaty and doesn't require Senate approval.

What they are worried about (and it's not just the GOP - there is bi-partisan support for a Senate ratification process) is that Obama would rather get a deal done even though the deal may not be a good deal.  The concern is that he's just not tough enough to force the Iranians into a compromise that can actually do what the negotiations are supposed to do - end Iran's quest to make a nuclear weapon.