I’m not sure Sanders was any different on immigration at this time (he voted with the Minutemen in 2006) and was praised by anti-immigrant group NumbersUSA in 2016 for his views on immigration in the past.
Sanders, in the House, voted for a Jack Kingston amendment supporting the Minutemen based on some bizarre conspiracy theory. buzzfeednews.com/article/evanmc…
(SPLC designated the Minutemen a hate group the year before.)
Trump supporters refer to the Steele memos as "discredited" or "debunked." News organizations often refer to it as "unverified." However, claims for which there's publicly available information have held up quite well. Annotated memos: corrupt.af/dossier
Here's a thread of claims made in the Steele memos with publicly available information from reputable sources.
"Source B asserted that the TRUMP operation was both supported and directed by Russian President Vladimir PUTIN."
U.S. intelligence concluded that Putin himself ordered the attack on the 2016 election. nytimes.com/2017/01/06/us/…