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_20799587_1 ( obama_number INTEGER, mccain_percentage VARCHAR )

### Question ###
How many people voted for Obama in the county where McCain got 72.75% of the votes?

### Accurate SQL ###

SELECT MIN(obama_number) FROM table_20799587_1 WHERE mccain_percentage = "72.75%"