No. Read the methodology statement carefully. They have 1000 respondents to the entire poll. When they refer to the data by a stratified group, they only present it if the number of people in that group is 125 or greater.
For the poll questions that specifically say. “For voters registered as Democrats or democrat-leaning independents”, the response Pool is cut down to something like 450 (the exact number is listed in the description). If they then divide that into four age groups, then it would actually be reasonable for NONE of them to exceed 125 respondents.
If you look at other breakdowns in the survey, it is clear that all of the age groups and demographics are covered.
Also note that polls results are almost always corrected after the fact for sampling error - so if they get a low response rate from 20-30 year olds, then they weight those responses more heavily so that they represent the expected proportion of the overall population.
For the poll questions that specifically say. “For voters registered as Democrats or democrat-leaning independents”, the response Pool is cut down to something like 450 (the exact number is listed in the description). If they then divide that into four age groups, then it would actually be reasonable for NONE of them to exceed 125 respondents.
If you look at other breakdowns in the survey, it is clear that all of the age groups and demographics are covered.
Also note that polls results are almost always corrected after the fact for sampling error - so if they get a low response rate from 20-30 year olds, then they weight those responses more heavily so that they represent the expected proportion of the overall population.