Are Republicans and Democrats preparing to settle their decade-long blood feud over immigration policy?

Not quite, but amid the ongoing polemics and finger-pointing, some promising signs of constructive engagement - driven largely by the two parties' shared fears and anxieties over the growing Latino vote -- have emerged in recent weeks.

Consider, for example, the somewhat surprising embrace by Democrats of Republican Senator Marco Rubio's compromise proposal on the long contested "DREAM Act," a bill that, in its current form, would legalize some 2 million undocumented immigrants who migrated illegally with their parents while still minors.

In April, Rubio, who'd previously denounced the DREAM Act as an unacceptable "amnesty," floated a new proposal that would allow the Act's intended beneficiaries to stay in the country legally, but only on a temporary visa. They wouldn't get an automatic ticket to citizenship, as the Act in its current form would allow, and wouldn't be able to sponsor family members for legal residence, either. But they could still apply for a green card through regular U.S. immigration channels, which means, with a much longer wait, they'd likely end up as U.S. citizens anyway.

Largely caught off guard by Rubio's unexpected gambit, most Latino advocacy groups, as well as Los Angeles mayor Antonio Villaraigosa and Senate majority leader Harry Reid initially responded with outrage. Reid argued that Rubio's proposal would turn the DREAM Act beneficiaries into "second class citizens" -- here to work but not to vote, and living in legal limbo, possibly for years. Others suggested that Rubio was merely trying to create a fig leaf of legitimacy for the GOP with Latinos, while boosting his prospects of becoming Romney's running mate in the fall.

But it quickly became clear that the matter wasn't so simple. The word on the street was that many Latinos didn't necessarily care about the DREAM Act's promise of automatic citizenship - even a temporary visa was preferable to the ever-present threat of deportation. And Rubio had already vetted his proposal with Latino grassroots activists in his home state of Florida -- a key November battleground, of course -- and had secured their tentative support. It wasn't long before Rep. Luis Gutierrez, who heads the immigration reform caucus in the House, was secretly sitting down with Rubio to discuss the outlines of a future deal, and pledging to work with a man that he'd once denounced as an "extremist."

Bipartisanship also appears to be breaking out on a second immigration reform front: whether to loosen current visa restrictions to allow more foreign-born scientists and engineers to obtain green cards more quickly. The measure would apply to prospective overseas workers but also to foreign-born students in American universities who account for an unusually high percentage of graduating PhDs. Like Dream Act supporters, U.S businesses like Microsoft have been pushing their visa reform measure for years, largely to no avail. But in recent weeks they've ramped up their efforts, winning fresh backing from Rubio and from two Democratic Senators, Mark Warner of Virginia and Chris Coons of Delaware

Even Obama, anxious to demonstrate progress on the jobs front, has begun promoting a bipartisan immigration bill that would reward foreign-born entrepreneurs with green cards if they demonstrate an ability to boost domestic employment. Various studies have documented that immigrants start businesses at a much higher-rate than native-born Americans - 50% higher, in some cases - and that many of those businesses have helped revitalize blighted neighborhoods in numerous metropolitan areas. In a recent op-ed, the bill's supporters, including the ever-present Rubio, pledged to work closely with Obama and the White House to secure its speedy passage.

What's motivating this sudden burst of bipartisan enthusiasm for immigration? Politics, of course, and a growing sense that Latino and non-Latino voters alike have become fed up with the current impasse. In a sign of just how frustrated some leading U.S. business and political figures have become, New York Mayor Michael Bloomberg, normally a close ally of Obama, last week blasted the President and both political parties in Congress, suggesting that they were "playing politics" with immigration rather than simply getting down to business. Bloomberg even went so far as to suggest that some states be "forced" to accept more immigrants while some like New York be allowed to set their own visa policies in the absence of federal action, a position that bears a striking resemblance to legislation that disenchanted Republicans in states like Utah passed last year.

All of these developments are suggestive of how quickly -- though still imperceptibly, it seems -- the political terrain on immigration may be shifting. All-but-certain GOP presidential nominee Mitt Romney, who first seemed to demur when asked about Rubio's Dream Act compromise, has since quietly embraced it. And while Romney still trails Obama among Latinos by a wide margin, he's already started closing the gap, recently earning 27 percent support, nearly double the level he recorded in earlier polls, and already narrower than the margin that separated Obama and John McCain in 2008.

Some conservatives, including Rubio and former House speaker Newt Gingrich, who savaged Romney's immigration stance during the GOP primaries, are predicting that Latino concerns over the economy are likely to push them even closer to Romney, especially as the election grows near and the candidate continues to pivot tactically to the center.

Wishful thinking, perhaps, given the GOP base's persistent hostility to illegal immigrants and its continuing hold on Romney, but Obama and the Democrats can't afford to assume that Republicans will eventually revert to type. The U.S. Supreme Court is about to rule on the constitutionality of Arizona's tough immigration enforcement law at a time when the administration itself has already pushed deportations (mostly of Latinos) to record levels. If the Court, as expected, rules in Arizona's favor -- at least on the core issue of the state's right to aggressively enforce federal law -- there will be growing pressure on the White House to do even more on immigration, or risk alienating its base still further.

In fact, Rubio is now pushing the GOP to try to pass a modified DREAM Act and other immigration measures before November in the hopes of upstaging Obama and the Democrats. He's recently been joined in this push by New Mexico's Tea Party-backed governor Susana Martinez, a tough-talking former prosecutor who like Rubio has been prominently mentioned in recent months as a possible Romney running mate. Such a push, even for rhetorical purposes, could well turn the tables on Obama by making the GOP look like the principled "party of compromise," and the Democrats, still holding out for a more sweeping -- but politically unrealistic -- amnesty plan, as the stubborn "party of no."

Of course, looming over these calculations is the reality that the 2012 presidential race is tightening, not only nationally, but in Florida, Nevada, Colorado, and even Virginia, Latino-rich battleground states that Obama carried handily in 2008. The four states are facing huge economic problems that affect Latinos disproportionately, and while John McCain lost the Latino vote to Obama in 2008, experts say that a relatively weak Latino turn-out -- which, based on the latest Census data is likely -- will further shrink Obama's demographic advantage. Given how large the Latino vote is in these four states -- ranging from 14 percent in Nevada to 40 percent in New Mexico -- a relatively small Latino voting swing could easily decide the outcome.

All of this places the Obama administration, which is accustomed to brow-beating the GOP on immigration, in an exceedingly difficult position. The more Rubio & Co. keep pushing for legislative compromise, the more likely it will give Republicans -- and Romney -- a fresh opening with Latino voters. Whether this tactical GOP shift leads to enduring bipartisan compromise after the dust from the election settles remains to be seen, of course. But for immigrants who've grown accustomed to little more than blatant pandering by the two parties, any sign of substantive movement is surely good news. For Democrats more than Republicans, though, it could prove an unwelcome challenge.