This is cross-posted from over at the Off the Bus project at Huffington Post.--------- As the cost of running for president and Congress continues to rise, candidates must ask for more and more money from big donors. A new analysis by the Center for Responsive Politics shows that the top giving industries and interests -- all with major stakes in decisions the new president and Congress will make--are happy to oblige.  Contributions to candidates and national party committees from top giving interests are up 46 percent from the same time four years ago. Compared with the first three quarters of 2006, contributions from the top 50 industries are up over 50 percent.  So, who's fueling the increase? Industries that might very well be effected by who takes over the White House and who controls the gavel in Congress. The investment and securities industry (including hedge funds and private-equity firms) has increased its giving nearly 91 percent from 2004. This is the same industry that is facing increasing scrutiny from legislators who feel like these wealthy investors aren't paying their fair share.  With the housing market in a historic slump, real estate interests want to make sure their voices are heard when Congress and the President make a decision on whether to intervene or not. They've increased their contributions by 51 percent. The healthcare industry, hearing quotidian stump speeches about the broken system and suggestions for ways to change it, want to be part of the discussion as well. And they're making sure they will be by increasing their contributions by 23 percent.  And while many of the major presidential candidates have balked at having to take special interest money, they know they have to if they want to win. In August, Sen. Barack Obama (D-IL) said, "The argument is not that I'm pristine, because I'm swimming in the same muddy water [as the other candidates]. The argument is that I know it's muddy and I want to clean it up."  Many of them also support public financing systems similar to the Fair Elections Now Act that would bring full public financing to the Senate and legislation sponsored by Sen. Russ Feingold (D-WI) that would fix the "broken" presidential system. Until then, candidates will have to wade through the "muddy water."