The Wisconsin primary is February 19. Pay attention to the results, because it may be an indicator of where the Democratic race is headed. Why, you ask? Wisconsin is a primary. Clinton has outperformed Obama in primaries in the past. (His strength is in caucuses.) But the demographic factors which have so far favored Clinton and Obama won't be present in Wisconsin. Look at the numbers. Wisconsin has a low black population (5.9 percent) and a low Latino population (4.6 percent). So Obama and Clinton will be competing for the white vote. If Obama can win white men, as he did in California, it may be enough for him to win or pull even with Clinton, who will no doubt enjoy a large majority of votes from white women. But even winning the white male vote may not be enough. To win Wisconsin, Obama will have to win white men and at least a plurality of white women. That's a tall order. Obama is expected to do well in next week's Potomac Primary. But, as happens so often in this campaign, the storyline the week after next may rob him of momentum once again, centering on his failure to win Wisconsin.