Super PACs and dark money groups have spent more than $1.9 million to boost the campaigns of congressional incumbents with primaries tomorrow — Super Tuesday, for folks just in from another planet. And even as voters prepare to go to the polls, the donors of some of that money remain undisclosed.

Races in the Heart of Dixie and the Longhorn State have been the biggest magnets for independent expenditures by those groups. All but $143,113 of the $1.9 million spent so far by outside groups in Super Tuesday states went to contests in Alabama or Texas, most of it supporting the incumbents.

more at Source: Ahead of Super Tuesday, outside spending — some of it dark — props up incumbents | OpenSecrets Blog