The Thomas H Lee Company is very, very blue. They are the partners in this, along with Texas Pacific Group, which has a lot of blue contributors. (As does Bain. They have been operating out of Boston, MA and have been about 60-40 Repub to Dem contributions.)

Look at some of Thomas H Lee's contributions. (Via www.fec.gov )

LEE, THOMAS H
BOSTON, MA 02109
THOMAS H LEE COMPANY

DSCC/NON-FED UNINCORP ASSOC
10/02/2002 10000.00 22020813535
10/09/2002 10000.00 22020813551
10/31/2002 25000.00 22020892355

DEMOCRATIC SENATORIAL CAMPAIGN COMMITTEE
12/31/2003 25000.00 24020023546

DEMOCRATIC SENATORIAL CAMPAIGN COMMITTEE
07/13/2005 26700.00 25020350959

DEMOCRATIC SENATORIAL CAMPAIGN COMMITTEE
06/20/2006 4700.00 26020541033

DEMOCRATIC SENATORIAL CAMPAIGN COMMITTEE
06/20/2001 8333.00 21020090265