The Romney campaign makes a strong case that he may well prevail in November. As Mark Halperin summarized: “Team Romney remains convinced that voters crave a more concrete form of hope and change, and that the anemic economy and the President’s failure to crack the 50% mark in most polls means he is destined to lose, maybe big, in November.”

Nevertheless, the Obama team remains cautiously confident that they are on track to win reelection for the President. As David Plouffe put it in an interview with me, while Obama advisers fully expect the race to be extremely close until the end, as long as he maintains a small but persistent lead in the battleground states, “we’re right on the cusp of victory.”

Here’s a partial list of reasons the Obama team is cautiously confident:

1) Romney cannot win over true undecided voters in the lopsided numbers he needs if he remains two to three points behind in the key battleground states. The Obama team thinks far more about state polling than national surveys, and right now, according to Nate Silver’s projections, Obama has at least a three point lead in Colorado, Iowa, Nevada, and Wisconsin, and nearly as big a lead in Virginia. The Obama team believes it holds leads in these battlegrounds; Dems think Pennsylvania, Michigan, and Minnesota are out of Romney’s reach.

The Romney camp seems to be hoping for a big, late break of undecided voters his way. But Dems remain convinced they understand who these voters are and what motivates them better than the Romney team does — and don’t see a way that these voters break to Romney in large enough numbers to overcome a two or three point deficit in the key battlegrounds.

“The question is, Is Romney going to get enough of the undecided vote to overcome a two or three point deficit in the battle ground states?” Plouffe told me. “Most assuredly not.”

2) The fact that Obama has not cracked 50 percent is not the harbinger of victory Romney thinks it is. When I asked Plouffe to respond to the Romney argument about Obama’s failure to reach 50 percent, he claimed this is still premised on a faulty assumption — that this signals Romney will capture an unduly large share of the remaining undecided voters. If Obama heads into early voting with 48 or 49 percent in the key battlegrounds, and a small lead, Romney will not be able to make up that deficit, Plouffe argued.

“We think these people are not going to break decidedly against us,” Plouffe said. “The fact that we’re polling at 48 or 49 in these battlegrounds is a big deal, because we’re right on the cusp of victory.”

This, again, turns on who these voters are. Dems believe that there are fewer than three million true undecided voters in the battlegrounds who will decide the outcome; Dems think they are disproportionately made up of independent women and college educated men under 40 who are also independents — two groups that simply won’t break towards Romney in overwhelming numbers, given the Dem campaign’s emphasis on women’s issues, and core differences between the two candidates over issues that matter to college educated voters.

Dems think Romney simply must figure out a way to bring Obama down a point or two in the key battlegrounds, and boost Romney up a point or two — he must bring this race closer to a tie if he is to win.

3) The Obama campaign believes it has neutralized the welfare attack. Romney is investing heavily in ads falsely claiming Obama gutted welfare reform. Dems initially viewed this as a threat. In their view, undecided voters were processing the attack as follows: The voters didn’t think this sounded like something Obama would do, but if it were true, it would worry them.

That’s why Dems responded so aggressively to debunk the claim; Dems believe the local press in the battlegrounds has handled the issue responsibly and has communicated clearly to undecided voters that it’s false. Dems think the attacks are not resonating significantly with true undecideds, who just don't see Obama as someone who favors a culture of dependency or “welfare check” handouts.

“That’s not what voters think about President Obama,” Plouffe said of Romney’s welfare claims. “There’s a resistance to it. They say, ‘I haven’t heard that; I’m not sure, that doesn’t seem like something Obama would do.’ And then they get reassured, and say, ‘Okay, he’s not doing it.’ ”

This is only a partial list; Dems believe Romney will fail to significantly narrow the gender gap or reverse his historic deficit among Latinos, particularly with a Dem convention focused so heavily on those groups. Dems also believe Romney failed at his convention to articulate a clear case for what he would do for the middle class — a major error.

It can’t be restated strongly enough that Obama officials fully expect this race to be extremely close until the end. Hundreds of millions of dollars in ads are set to be unleashed, and there are plenty of land mines, economic and otherwise, littering the path to victory. And it will all come down to turnout, which is unpredictable. But right now, Dems are cautiously confident of victory.