The conventional wisdom is that 2014's five point loss was simply a repeat of 2010's five point loss, but if you look at the county-by-county vote margin numbers you see that isn't really the case.
Nationwide, about 90% of counties saw a decrease in turnout from 2010 to 2014 and nearly all of those saw a decreases in Dem vote margins. However, in Wisconsin every county saw increased turnout and Dems saw improvement in vote margins in half of Wisconsin's counties from 2010 to 2014.
In theory, if Dems improved their margins in half of the counties, including the two largest counties, the dems should have improved enough to win in 2014-- keeping mind that 2010's five point loss was relatively close. However, what happened is that although Burke ran up much larger margins in five of Wisconsin's larger counties, Walker responded with larger margins in ten of Wisconsin's larger counties in the Fox Valley and the so-called "Ring of Fire" Miwaukee suburb counties. And although Walker was moving in the wrong direction in half the state, he made up for it with a dramatically improved performance in the other half of the state.