President Barack Obama took the fiscal cliff from the tight circle of negotiators at the White House to a sprawling auto factory floor on Monday, as he continued the two-pronged public-private approach he has been using to push his plan to raise taxes on the wealthy.

While aboard Air Force One en route to Michigan, Obama called Senate Majority Leader Harry Reid, D-Nev., to update him on the talks, which included an in-person session Sunday at the White House with Speaker John A. Boehner, R-Ohio.

Though the details of the ongoing negotiations are fuzzy, the key players are talking, which is more than could be said a week ago.

However, the primary differences between the two sides remain. Boehner’s office said the speaker is waiting for the White House to come back to Republicans with more spending cuts. And the White House says the president is waiting for the GOP to give more on revenue. Two years of fighting over how to rein in the federal debt is now coming down to two weeks of deal-making at best and he-said/she-said at worst.

“The Republican offer made last week remains the Republican offer, and we continue to wait for the president to identify the spending cuts he’s willing to make as part of the ‘balanced’ approach he promised the American people,” said Boehner spokesman Michael Steel, who confirmed conversations with the White House “are taking place” but declined to specify the nature of those talks.

White House Press Secretary Jay Carney told reporters aboard Air Force One that Obama has offered specifics on cuts — pointing to the president’s original deficit reduction plan that has repeatedly been dismissed by the GOP. Carney added that the Republicans are the ones stalling talks by not giving more detail on what they would be willing to do on revenue.

“What we haven’t seen yet is any specificity at all from Republicans on revenue; we’ve seen a sentence on revenue. And while there have been encouraging statements by individual lawmakers about the realization that rates will go up on the top 2 percent, we haven’t seen anything specific from Republicans with regard to that,” Carney said.

Indeed, the number of rank-and-file Republicans who seem to endorse ceding the tax rate battle in order to gain leverage in a larger fight on raising the debt ceiling and cutting entitlement spending is growing.

On Sunday, for example, Sen. Bob Corker, R-Tenn., said congressional Republicans are starting to realize they don’t have leverage in the pre-Christmas debate.

“There is a growing group of folks that are looking at this and realizing that we don’t have a lot of cards as it relates to the tax issue before year-end,” Corker told “Fox News Sunday.” “A lot of people are putting forth a theory, and I actually think it has merit, where you go ahead and give the president the 2 percent increase that he is talking about, the rate increase on the top 2 percent. And all of a sudden, the shift goes back to entitlements … and maybe it puts us in a place where we actually can do something that really saves the nation.”

Corker has previously talked about his own flexibility on tax increases.

For his part, Carney on Monday reiterated, “There is no deal without acknowledgment and acceptance of the fact that rates are going up on top earners.”

Republicans have come to the table with an $800 billion offer on revenue, the same as in the summer of 2011, which Carney said is “far, far short of the necessary revenue for a comprehensive deal that achieves $4 trillion in deficit reduction.”

While Carney talked to reporters, Obama took his case to the public.

“I’m willing to compromise a little bit,” Obama said at an event in Michigan. “But if we’re serious about reducing our deficit, we’ve also got to be serious about investing in the things that help us grow and make the middle class strong, like education, and research and development, and making sure kids can go to college, and rebuilding our roads and our infrastructure. We’ve got to do that.”