With a little more than 2 weeks to go before Iowa votes, there is not much more the campaigns can do to move numbers but ground game, organizing and getting their supporters worked up. This is the time 527s -- independent groups which can spend thousands of behalf of candidates but are not allowed to coordinate in any way with any campaign -- jump in and start helping their chosen candidates.
Among Democrats, the two main stories for now have been (1) how little negativity there has been in 527 ads -- a stark contrast from 4 years ago where Dean and Gephardt bashed each other through independent groups, and (2) the fact that no 527 has jumped in on Obama's behalf.
Politico's Ben Smith tallied up the totals as of Thursday night and found three groups (AFSCME, AFT and Emily's List) agitating on Clinton's behalf for a total of more than $1,8 million; and two groups (the Carpenters union, and SEIU) working on Edwards's behalf for a total of almost $1.3 million.
Since then two big developments: "The Alliance for a New America" (seemingly funded by the SEIU) has dumped in nearly 3/4s of a million to help Edwards and run tons of ads across the state in the week after Christmas; and FEC filings show that pro-Hillary group spent $300,000 dollars in a single day yesterday, with most of it coming from Emily's List. It is unclear where the money will be used, but probably in Iowa the most and New Hampshire to some degree. There have also been very small groups that have been spent very little money but hoped for some publicity (such as "Democratic Courage" which prepared negative ads against Obama and against Clinton).