In the case of people, this is a popular misconception. Democrats are funded by more billionaires than Republicans, are in control of a majority of the wealthiest congressional districts, and among people earning more than $200,000 the presidential vote was very evenly split.
http://www.politifact.com/truth-o-meter/article/2014/jun/23/...
https://www.nytimes.com/2015/10/07/opinion/how-did-the-democ...
http://ijr.com/2014/02/116056-wall-street-bankers-top-donors...
http://www.nytimes.com/interactive/2016/11/08/us/elections/e...