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_23812 ( "Date of opinion poll" text, "Conductor" text, "Sample size" real, "For" text, "Against" text, "Undecided" text )

### Question ###
Who conducted the poll with sample size of 2000 that shows 18% undecided?

### Accurate SQL ###

SELECT "Conductor" FROM table_23812 WHERE "Undecided" = '18%' AND "Sample size" = '2000'