It’s not just Iowa; Biden’s national numbers are also dropping:
538’s latest national polls:
Ipsos, 5/29-6/5: Biden 31%
YouGov, 6/2-4: Biden 27%
CNN, 5/28-31: Biden 32%
Looking less invincible by the day. 
It’s not just Iowa; Biden’s national numbers are also dropping:
538’s latest national polls:
Ipsos, 5/29-6/5: Biden 31%
YouGov, 6/2-4: Biden 27%
CNN, 5/28-31: Biden 32%
Looking less invincible by the day.