As things stand now, a House and Senate conference committee is the only hope that Democrats and Republicans can reach agreement on border security and avoid another government shutdown. The negotiations — such as they are, for a committee that has met briefly only once in more than a week — are ostensibly between Republicans and Democrats. But well-informed Republicans believe it is another set of talks — internal talks among Democrats — that will determine whether the committee succeeds and a shutdown is averted.

"This is not a negotiation between Republicans and Democrats," said one GOP lawmaker who is keeping close tabs on the process. "This is a negotiation between rank-and-file Democrats and Nancy Pelosi."

"That is unmistakably true," added a Republican who is taking part in the talks. "There are many reasonable voices within the Democratic conference who want to see a positive resolution here." The speaker of the House's "emboldened stance" — her decision to refuse to consider any funds for a border barrier — has been "very hurtful to the process," the lawmaker added.

Why are the intra-Democratic talks so critical? Because Republicans already agree on the key components of a border security package. They are united behind the need for a border barrier, and they are united behind the other provisions — drug detection technology for ports of entry, more immigration judges, humanitarian aid for detained migrants — that many members of both parties support as part of a comprehensive border security policy. Republicans are already there.

[Also read: Democrats push to revive Obama-era aid to illegal immigrants in border talks]

The question is whether the California Democrat can be talked down from her my-way-or-the-highway position.

Some members of the conference committee — not just Republicans — were surprised when Pelosi made an opening offer that not only zeroed out the $1.6 billion for border fencing that Democrats had previously agreed to, but also zeroed out any money for new Border Patrol agents and slashed funds for Immigration and Customs Enforcement detention facilities.

"There is not going to be any wall money in the legislation," Pelosi said. Mentioning some already-existing vehicle fencing — fencing that has been overrun by illegal crossings in recent weeks — Pelosi said, "If the president wants to call that a wall, he can call that a wall."

The White House has indicated at several times during the past few months that it is willing to compromise on the amount of money devoted to a barrier.

Republicans believe there are Democrats on the conference committee and in the larger Democratic conference who do not share Pelosi's immoderation. "It's the Blue Dogs and a lot of the New Democrats," said the Republican who is taking part in the talks. "There is broad support within [Pelosi's] conference to resolve this. It's not just Collin Peterson."

Peterson is the Minnesota Democratic congressman who made news two weeks ago when he said, "Give Trump the money." During a radio interview, Peterson added, "I'd give him the whole thing ... and put strings on it so you make sure he puts the wall where it needs to be. Why are we fighting over this? We're going to build that wall anyway, at some time."

Needless to say, that is not the current position of Peterson's Democratic leadership. But where, exactly, most Democrats stand on the barrier issue is not entirely clear. Take the Fox News Sunday interview with Democratic Rep. Henry Cueller, a conference committee member who also represents a border district in Texas.

"First of all, we're not going to have a wall," Cueller began, sticking with his leadership. But then: "Now, can we look at some sort of enhanced barrier? That's something we can certainly look at."

Even granting that "look at" does not mean "support," what did that mean? Did that mean Democrats might support, say, replacing Pelosi's vehicle fencing with a barrier that stops pedestrians? Did it mean Democrats might support barriers in areas that currently have no fencing at all? Did it mean there might be some distance between more moderate Democrats and Pelosi's extremism?

Cueller did not explain. Instead, he attempted to make a sort of federalism argument in which local authorities, not the federal government, should control security on the U.S.-Mexico border.

"I have to say, living on the border, you have to let the local Border Patrol chief have the say-so and let the local communities be involved so they can come up with maybe some sort of enhanced barrier," Cueller said. "But again, Washington cannot dictate what sort of barrier and where to put it at."

If there is any argument that will not carry the day with either party, it is that one. The federal government has the authority to enforce immigration law, and in the end Washington, will indeed determine what, if any, new security measures are put in place on the border. By the time Cuellar was finished, there was absolutely zero clarity on whether there is a Democratic position different from Pelosi's.

Republicans believe that such a position does exist and that it could form the basis of a settlement of the current standoff. But for that to happen, Pelosi would have to back away from a stance — walls are immoral — that won the last shutdown fight. She didn't give an inch and came out on top. Why would she be inclined to make concessions now, even if some in her party believe it would be best for the country to do so?