All this talk about how we need a liberal knight in shiny gold Armour to ride to the rescue of the Democratic Party overlooks a couple of fundamental points.
1] Buying an election goes against fundamental democratic principles.
2] Giving money to politicians goes against the grain when money can be donated directly to "worthy" projects important to the person giving the money.
Whereas rich Republicans will do so because:
1] They regard politicians as fundamentally corrupt and as pawns in the power game.
2] They believe they are investing in a system that will profit them personally and more importantly give them more power.
You just have to look at what the Bill and Melinda Gates Foundation Invest in:
The United States Program for example
Early Learning
Emergency Relief
High Schools
Family Homelessness
Libraries
Pacific Northwest Community Grants
Postsecondary Education
Scholarships
Pretty much what most of us believe the government should be doing in the first place, in other words they are trying to fill the gap.
A common theme is that both the left and the right have little faith in government but long for a very different end game.
Republicans will try and buy the system.
Progressives will try and improve peoples lives directly.
Politicians are about as popular as pediculus humanus corporis in my family, hence money spent aiding them is seen as somewhat pointless when that money can be spent directly helping those that need it most. Sure they give to campaigns, but not so much as to be seen to be distorting an already corrupt system; Republicans have no such qualms.
So you believe either
Democracy can be bought and sold.
or
Whilst flawed it is the best system we have at this time.
There is a fundamental ideology gap.