If you think she only did it for the money, you haven't even 'scratched the surface'. [=there are many other factors, reasons, etc., involved]
Despite the 'surface' differences between the two candidates, they are very similar in most ways.
The tension between them is beginning to 'rise to the surface'. [=it is becoming easy to see]
(..) Fat of the land! No! Don't pull it, don't pull it! - Oh, God! - Give me another one. As the fat renders, the tallows float to the surface. Like in Boy Scouts. - It's hard to imagine you as a Boy Scout. - Keep stirring. Once the tallow hardens, you skim off a layer of glycerin. (..)1999 Fight Club