The DSCC’s decision to scale back its ad campaign in Pennsylvania is likely due to the fact that Democrats are now being forced to spend money on other competitive races in states like West Virginia.

According to the source in Pennsylvania, the DSCC has purchased TV ads for the coming week only in the Pittsburgh media market, where Democrats are facing particularly bad poll numbers. Pro-Toomey groups will be heavily outspending Sestak and Senate Democrats this week, says our source: “Sestak plus DSCC is smaller in every market, except Pittsburgh, than Toomey plus the Club for Growth plus American Crossroads.”