I am looking to explore the impact of 3rd parties on mainstream political parties in the United States. Not necessarily at the federal level but at state level too, and across any branch of the federal Government.
There are of course the most significant occurrences in history, such as Ross Perot's independent run in 1992 and 1996. But even more recently, the 2020 US senate election in Georgia saw the libertarian party deny either candidate 50% of the vote. Additionally, the green party was able to detract enough votes from Clinton in Michigan and Pennsylvania in 2016 to prevent her from winning. These are just some recent examples but of course there are many more. However, the above instances are mine, and others', mere assumption about which party the 3rd party impacted the most.
I'm looking to find if there has been any studies into the impact of 3rd parties in US elections, and which party their presence hinders the most. I've looked here, but the only available data was exit polling information, and I'm curious if there have been more rigorous approaches to examining this that go beyond exit polls.
This is my first question on this forum of StackExchange, I hope I have satisfied the requirements for a good question.