Table: vacancy_successors_2
Columns: district
vacator
reason_for_change
successor
date_successor_seated

Question: Who left a seat open for the district of connecticut at-large
SQL: SELECT "vacator" FROM vacancy_successors_2 WHERE "district" = 'Connecticut At-large'

Question: Why was a seat left open fo Connecticut at-large?
SQL: SELECT "reason_for_change" FROM vacancy_successors_2 WHERE "district" = 'Connecticut At-large'