Monsanto profits on farm subsidies indirectly. Because corn and soybeans are the most widely grown crops, and because monsanto produces those seeds, and because the farms those seeds are used on are subsidized, Monsanto benefits from those subsidies. It's really rather straight forward.

US farms today are on average much larger than they've been in the past, and there are fewer people working on them. Now a lot of that is what we'd call economic efficiency, which when making widgets is generally good. Thing is, food isn't a widget. How food is made has direct consequences in public health. Massive mono-cropping, the kind that Monsanto supports, and that absorbs the bulk of farm subsidies is bad from both a public health, and environmental standpoint.

Now when I say public health, I am not saying that GMOs are making people sick. GMO crops are largely responsible for the spread of obesity, but not because of being GMOs, but because of the role they play in the food system by essentially making corn and soybeans so easy to produce, and so profitable (farm subsidies here again), we have more of these crops than we need. We need to drive down the price of kale and broccoli, not corn.

This is not a simple problem, but the gist is that farms are larger now than they've been. There is also a split between large and small scale farms (there is the added issue of what a "family farm" is, in my reference I was meaning small farms, <50 acres, which make up half of all farms, but I concede that was not a good term to use). Large scale farms, including corn, soybeans, and the meat they support (the chain is short, cheap corn means cheap sugar, but it also makes raising cattle cheaper, and red meat is widely known to damaging to health, especially with regard to heart disease).

By redirecting farm subsidies away from large scale mono-cropping, and towards small, multi-use farms (the sort of folks at the farmers' market, my version of "family farmer"), we can reduce the cost of high quality, nutrient dense foods, and reduce the market competitive advantage that subsidies have currently awarded to just the kind of food that we need to be eating less of.

So yes, Joni Ernst has benefited from an especially wasteful, and arguably harmful government benefit program, one that she would almost certainly never do anything to threaten.