(DC) The Foundation Center’s database and analytic website entitled Foundation Funding for US Democracy is full of interesting information and worth detailed exploration.
Drawing on tax forms, the site categorizes $5.5 billion in grants made to strengthen democracy in the USA since 2011.
The ideological range is wide: the DeVos and Mercer foundations are in the database, along with Open Society and many more.
This is the distribution of grants by very broad categories, with a somewhat more detailed look at the pie slice devoted to “civic participation” (which interests me most).

I estimate that $1.73 billion of the $5.5 billion (31%) has gone to nonprofits headquartered in DC or the surrounding counties in Maryland and Virginia. With some exceptions, these are professional organizations without a grassroots membership base.
Within the category of “civic participation,” $2.1 billion has been distributed for the following purposes. These categories are non-exclusive; a grant can serve more than one purpose.

A total of $23 million–.0.43% of all democracy funding and a little less than one cent per American per year–has been spent on grassroots organizing for civic participation. I think that marks a major deficit.