By Tom Boggioni Reacting to continuous reporting from polling expert Sarah Longwell that Donald Trump’s popularity is waning with conservative and Republican voters, pollster Rich Thau and Jill Ditommaso sat down with Missouri voters — who are headed to the polls on Tuesday — to see how the former president is doing in the “Show Me ” state. In two words: not well. In a report for the Bulwark , they claim that a focus group of 13 Republican voters — none of them swing voters — were tepid at best at the prospect of a third Trump presidential run. Responses to how they felt about Trump jumpin…