So I tried to look up the "Democracy Institute" in 538's ratings of pollsters, but it isn't listed. The Sunday Express is an offshoot of the UK's Daily Express, a rightwing tabloid which I had mostly heard of because of its anti-immigrant hysteria.
So here's my question: why does Breitbart think that crowing about a dubious poll will help its cause at all? I guess the site exists by giving the wingnuts what they want to read, so maybe this is just about keeping the clicks coming rather than anything that will rescue Trump's reelection chances.
UPDATE: The second link above is working now. Except it isn't a link to the poll report, but rather an article in the Sunday Express about the poll results. There is no information, for example, about how the pollster weighed the results, the sample size, how respondents were contacted, or the margin of error. The articles does mention that 84% of the respondents identified as Republican. So that alone might explain the results. Actually, a 48% to 46% Trump lead over Biden from a sample that is 84% Republican is a pretty disastrous poll for Trump. They just don't spin it that way.