A new email out from Organizing for America suggests that President Obama's campaign arm is setting its sights on Sen. Bill Nelson (D-FL).

"[W]e need to bring grassroots pressure directly to our senators," the note reads.

Senator Bill Nelson and Senator Mel Martinez are both crucial votes in the fight for real reform, and we need to do everything we can here in Florida to show them that their constituents are standing up to demand change.

So we've organized events outside of their offices all across the state for tomorrow -- Thursday, July 23rd -- to demonstrate support for reform in Florida.

You might wonder why I characterize this as pressure on Nelson alone, when the email clearly names Sen. Mel Martinez (R-FL) as well. The answer can be found at this link, embedded within the email itself. Only one of the nine scheduled events targets Martinez (who is retiring this year). The other eight target Nelson.

Earlier this month, OFA ran ads in seven states including Florida. Those ads were silent about who, specifically, was being targeted, but these rallies make it clear: they're more concerned with Nelson. OFA is holding events in all 50 states, but, it's safe to say, isn't bringing this much pressure to bear on known quantities.