The faultline in the GOP revealed by the party's internal debate on immigration reform – over whether a future Republican coalition should rely more heavily on whites than it already does, or should try and bring more Latinos into the fold to win the presidency – remains unresolved. What we can say is that the last election and current polling suggest that the Republicans' path of least resistance is to win even more non-college-educated whites and to try to win somewhat more of the minority vote.

Start with the fact that in 2012 Obama lost a little more than 3pt off his margin of victory in 2008. That swing was not uniform. It's fairly clear that Obama's share fell significantly with white voters without a college education, stayed about level with whites with a college degree, gained a few points with Latinos, and may have lost a point or two with black voters.

I don't view the incongruity between those shifts as a sign that Obama should have done worse or better. In any election, you're given a certain amount of leverage by the state of the economy, and you need to use it where you can. In 2012, the parties found the coalitions that worked for them. It just so happened that Obama had more room for growth electorally because the economy was "good enough".

Indeed, there is little to no sign that Mitt Romney did worse than he should have, given the state of the economy. President Obama won by a little less than 4pt, when the two best fundamental models (based solely on numerous different economic factors) had him winning by 3pt and 5pt respectively. Taking into account Obama's approval rating and the economy, as the original Alan Abramowitz model does, shows Obama should have won by a little more than 4pt.

That's the reason why I don't buy the argument that the shrinking white population in this country necessarily spells doom for the Republicans. This is a two-party system where the economy almost always dictates who wins and loses elections. No one has yet proved that the 2012 election indicates that the Republican party needs to change fundamentally in order to win, despite hundreds of column inches expended on the subject.

For Republicans to win, they'd need economic conditions slightly more favorable to the out-party (that would have been, in 2012, a worse economy and less confidence). Following the 2012 pattern, this would allow them in 2016 to continue to do exponentially better among white working-class voters. Sean Trende, who believes that the GOP could win with a mostly white coalition, anticipates Republicans also gaining a few more points among minorities.

Of course, many doubt this steady-state strategy could work for Republicans. Karl Rove said a few months ago that Republicans would have a hard time regularly winning the white vote by 25pt or more. But that's the funny thing about electoral rules: they're made to be broken. For example, the aforementioned Alan Abramowitz said that Republicans would have a very hard time getting above the 58% of the white vote in 2010 that they had in 1994. In fact, they won 62% of the white vote in the last midterms.

That's why Trende has vigorously argued that the demographic wall facing the GOP doesn't really exist. The worsening Democratic performance among white voters we have seen recently is part of a longstanding trend. If the pattern continues, then white support for Democrats will continue to drop below its current historic low.

So, now we have a test case of sorts in 2014. The economy really hasn't gone south. Economic confidence is far higher than it was at the beginning of 2013, although it has stalled slightly. The percentage of those who view economic recovery as imminent has fallen slightly over the past few months, but it's only slightly lower than where it was at the time of the 2012 election. Put another way, there hasn't been that level of decline in the economy which many thought would need to happen for Republicans to win with the coalition they have.

Yet, Obama's net approval rating with white voters is no better than -25pt right now. His approval in Gallup's polling among white voters since the NSA leaks is now only 34.5%. That's a 4.5pt drop since the election. Pew has it slightly lower, at 33%, which is a 6pt drop off what Obama was showing in their final pre-election poll last year. It seems as though that wall keeps moving.

Most, if not all, of this drop for Obama is among whites without a college degree. Pew found support from that segment of the electorate dropping by a little less than 10pt. In other words, there is a continuity here with the November election result, in which Obama's support fell the furthest among whites without a college degree. If you think this might be pegged to public reaction to the Trayvon Martin case, the Zimmerman verdict and the president's response, it's not. Pew found college-educated whites reacted in the same way as non-college-educated whites to that issue – yet Obama has seen no decline in his standing among college-educated white voters.

Indeed, the swing looks much as expected: we have that drop among the non-college-educated whites, and among minorities to a smaller degree. We can see this by pooling Gallup's data since the Edward Snowden/NSA affair; this gives us a very large sample size. That's important because minority sample size in polls is often very small, which is why Pew and NBC News/Wall Street Journal differed so much in their minority findings this week. Gallup splits the difference and discovers that non-white approval of Obama has fallen since the election by 4pt, or about half of the drop we've seen with non-college-educated whites.

Now, things could change and this analysis may end up way out-of-date come 2016. I should also add that the eventual party coalitions may look somewhat different then, with Republicans winning back some African-American voters once Obama is out of office, but maybe also Democrats making a slight recovery with white voters.

But the most salient fact is that Obama's approval among registered voters is a weak 45% – and that's without a bad dip in the economy or any grave scandal. This soft approval rating gives credence to what the polling suggests: that the Republican party is most likely to win the White House in 2016 with a coalition that includes even more non-college-educated whites and a slight increase among minority voters.