FTT needs to get 60 votes in the senate to pass. Even if Dems manage to squeeze out a majority, they’re still not gonna have enough to pass it. It’s still a threat that has minimal chance at passing
If the Dems win the White House, Senate and the House they won't need 60 votes to pass a FTT. The Republicans passed substantial tax changes in 2018 with only 53 votes.
https://www.vox.com/policy-and-politics/2017/11/14/16634200/republican-tax-reform-byrd-rule