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_20278716_2 (mccain__percentage VARCHAR, others__percentage VARCHAR)

### Question ###
What percentage of voters chose McCain in the county where 2.1% of voters voted third party?

### Accurate SQL ###

SELECT mccain__percentage FROM table_20278716_2 WHERE others__percentage = "2.1%"