Which party has the highest number of legislators who are Baptist?
party that has the highest number of legislators refers to MAX(COUNT(party)); Baptist refers to religion_bio = 'Baptist';
SELECT T2.party FROM current AS T1 INNER JOIN `current-terms` AS T2 ON T1.bioguide_id = T2.bioguide WHERE T1.religion_bio = 'Baptist' GROUP BY T2.party ORDER BY COUNT(T2.party) DESC LIMIT 1