It’s hard to imagine Congressman Henry Brown is going to lose in his primary race next month, but the math presented by The Washington Post after last night’s surprise GOP loss in an ultra-conservative Mississippi Congressional district could mean trouble in the general election for Henry Brown.

I did a little bit of research on Mississippi’s 1st district over the weekend to try to get an accurate read on just how Republican it is. The Cook Political Report — a Fix alma mater — produces something called the Partisan Voting Index, a system that compares all House districts to one another based on their vote for president. That comparison produces a PVI score; if a district, for example, carries a PVI of D+5, it means that the seat voted five points more Democratic than the nation as a whole. Mississippi’s 1st has a PVI of R+10; only seven (now eight) Democrats represent districts with a PVI score of R+10 or higher.

That’s a long-winded way of saying that, if last night is any indication, Democrats may have a MUCH broader field of targets this fall than we previously thought.

Though we don’t want to ignore Brown’s status as an incumbent, District 1 is also ranked R+10.