Except I've actually given facts and statistics while you've given generic Democratic talking points.
You're right, it definitely is. But from the last two midterms, can you honestly find any indication the Obama coalition works in elections that don't have Obama, or that an old northeastern white woman is going to get the commanding support from minorities she needs to win?
You're right, it's not the 1950s. That's a good thing. However, whites still make up around 75% of the electorate - same as in 2008. If you are only drawing 40% of the white vote, like Obama did in 2012, you can make up for it by drawing absurd margins among minorities (93% of blacks, 71% of Hispanics, and 78% of Asians). The problem is, if those numbers slip up, and you keep losing white voters (which is the trend), you can't win. Let me explain how. As I noted earlier, in 2014 the demographics were virtually the same as 2008. Let's say that 2016 features the same demographics, but half the results (ie. take the midpoint between 2012 and 2014). That would mean:
*White (74%) - 60% Republican, 39% Democrat
*Black (13%) - 91% Democrat, 8% Republican
*Hispanic (9%) - 67% Democrat, 32% Republican
*Asian (3%) - 61% Democrat, 38% Republican
*Other (2%) - 54% Democrat, 43% Republican
129,085,403 people voted in 2012. So, let's do the math:
95,523,199 white voters - 57,313,919 Republican, 37,254,048 Democrat
16,781,103 black voters - 1,342,489 Republican, 15,270,804 Democrat
11,617,687 Hispanic voters - 3,717,660 Republican, 7,783,851 Democrat
3,872,563 Asian voters - 1,471,574 Republican, 2,362,264 Democrat
2,581,709 Other voters - 1,110,135 Republican, 1,394,123 Democrat
Total: 64,955,777 Republican, 64,065,090 Democrat
Each percentage point of the white vote is around 950,000 votes; a loss of one percentage point is a net less of 1.9 million votes. Each percentage point of the black vote is around 170,000 votes, each percentage point of the Hispanic vote is around 110,000 votes, each percentage point of the Asian vote is around 40,000 votes, and each percentage point of the other vote is around 26,000 votes. In other words, in order to make up a loss of just one percentage point of the white vote (1.9 million votes), Democrats would need to win 6 more percentage points of the black vote or 9 more percentage points of the Hispanic vote.
Both of those are difficult. If Romney had won three percentage points more of the white vote, he would have won, even with 2012's racial vote. But as I showed above, if 2014's demographic results don't slide more than halfway back to 2012's, Democrats can't win.