​Heat over Iran nuclear deal intensifies

GOP rips Iran nuclear deal as Biden pushes fo... 03:15

In an effort to change minds about the Iran nuclear deal, Vice President Biden will head to Capitol Hill Wednesday, but Republicans are entrenched in opposition. As President Obama prepares for a news conference later this afternoon, one senator says people are taking sides before even having read all the details, reports CBS News correspondent Nancy Cordes.

House Speaker John Boehner said he will do everything in his power to try to stop it.

What is in the Iran nuclear deal 03:40

"The deal that we have out there, in my view, from what I know thus far, is unacceptable," Boehner said.

Boehner's reaction was mild compared to that of some of his GOP colleagues who called the deal "dangerous" and "junior varsity foreign policy grounded in childlike optimism."

"This is considerably short of perfection, apparently," Sen. Majority Leader Mitch McConnell said.

He has a different idea for an acceptable deal.

"Describing the perfect deal, I guess, would be a deal under which Iran would not be able to acquire nuclear weapons," he said.

Republicans, and many Democrats, worry Iran will be allowed to keep some nuclear material, international inspectors would not be guaranteed blanket access to Iranian nuclear sites and an embargo on Iran buying conventional weapons could be lifted in just five years or sooner.

"I recommend this to all senators: Let's find out what we have first," Sen. Minority Leader Harry Reid said.

Special Report: President Obama announces Ira... 18:38

He said lawmakers are taking sides before they've even seen the fine print.

"They should look and read the agreement first. And I just think it's unfair for them to start charging out, determining now how they're going to vote on this," Reid said.

And former Secretary of State Hillary Clinton, visiting Democrats on Capitol Hill, called the deal an important step in stopping Iran's nuclear program.

"We have to treat this as an ongoing enforcement effort, which I certainly strongly support," Clinton said.

That puts the Democratic presidential contender at odds with many of her Republican rivals who say, if elected, they would move quickly to rescind the agreement. And because it isn't an international treaty, there wouldn't be anything to stop them, Cordes notes. But Mr. Obama has vowed to veto any measure killing the accord, and observers say mustering enough votes to override such a veto would be difficult.