Rasmussen was the least accurate in 2018, precisely because his "likely voters" model over samples republicans. He had the GOP +1, and the Dems actually won by 8.6. If you oversample Republicans then you believe that the "attacks" on Kavanaugh, the Caravans and the "walking away" nonsense were the primary driving force heading into the 2018 midterms. But the reality is that anti-Trump sentiment ended up being the driving force,and the numbers are even lower now.
Trump has shut down ads in MI, and is spending money on ads in Iowa and OH. That fact alone tells you his internal poll numbers are in the toilet. He only won MI in 2016 because Black turnout in Detroit was down. With the way, Trump has attacked Whitmer (which made her more popular) and the tremendous losses the Black community in Detroit suffered due to COVID, voter apathy will not be a factor in Michigan.
Biden already increased turnout in the Dem Primary by close to 250,000 more voters in 2020 over 2016. Right now Team Trump considers ad spend in MI as money down the drain. It's basically the same situation in both WI and PA as well, in addition to states like NC, FL, and GA where Trump trails as well...