They're feeling double pressure in the low to mid market because French and Italian wineries have started selling cheaper and cheaper bottles of wine into the American market. Trader Joes has always had the three buck chuck (née two buck chuck) which I consider barely drinkable but now they've got an Italian Pinot Grigio for $3.50 [1] which has been surprisingly good and hasn't run out of stock despite being very popular. They've also got a good $5 French rose and my friends have been praising some of their cheap reds.
Imagine how cheap it must be to produce if an imported bottle costs $3.50.