Consider this for a political wild card. The anniversary of the September 11 terrorist attacks is only six days before the September 17 Massachusetts primary, which gives the gubernatorial campaigns an incredibly limited window of time to reach voters.

The conventional wisdom holds that voters generally tune out through the summer months and pay attention to politics only after Labor Day. This year, Labor Day falls on September 2, and September 11 falls a little more than a week after the Tuesday when everybody gets back to work.

There is some speculation that the campaigns may have to refrain from advertising on the days surrounding the anniversary — and on the anniversary itself — to convey the solemnity with which that day should be treated. But others say the 11th is exactly the right day to put on campaign advertising.

" The one day I think they’re going to watch is September 11, " says one political adviser. " I think everybody will buy that day. "

The bottom line is nobody knows how the 11th will play out. But it’s yet another element to factor into the equation.