Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_21789 ( "Poll Source" text, "Dates administered" text, "Democrat: John Lynch" text, "Republican: Joe Kenney" text, "Lead Margin" real )

### Question ###
Name the most lead margin for republican joe kenney being 23%

### Accurate SQL ###

SELECT MAX("Lead Margin") FROM table_21789 WHERE "Republican: Joe Kenney" = '23%'