While the Tea Party and the Occupy Wall Street movements disagree on many things, they both (early on, at least, in the case of the Tea Party) decried the rise of "crony capitalism". They recognized that the huge lobbying checks written to those in power cause huge, unfair distortions in the market, disproportionately helping the donors at the expense of the rest of us. The Tea Party in particular has been rabidly "anti-Washington". One would think that lobbyists and Washington insiders would be immensely unpopular with both crowds. The Tea Party's recent embrace of one Newton Leroy Gingrich demonstrates that this formerly-key principle of the movement has been abandoned, as Gingrich is entirely a creature of K Street, lobbying capital of the universe.
After Gingrich's resignation as Speaker, he spent the next decade making money off of his name and his connections in Washington. He set up numerous for-profit organizations to this end. These organizations are all located on K Street (as Rachel Maddow discussed yesterday; jump to 5:30 for the relevant section). He received at least $37 million just from health care organizations. While he never officially registered as a lobbyist, it's safe to assume that they weren't just paying him tens of millions for his perspective as a historian.
The Tea Party would lose all of its credibility if Newt, a literal creature of K Street, were to become the nominee. It would mark the completion of the Republican establishment's mission to subsume the Tea Party movement.