Probably most modern Baptists know the rule of a democratic majority, though some experience the top-down rule of pastoral dictatorship, elder rule or staff decision-making. Historically, the Baptist decision making process has also included consensus, the unanimous rule in matters of fellowship, and even the casting of lots. H. C. Vedder wrote that "The Baptists of the seventeenth century had many curious customs...Fasting was a common observance, feet-washing was practised by many churches, though its obligation was earnestly questioned, and the anointing of the sick was so common as to be almost the rule. Pastors and deacons were often elected by the casting of lots, and love feasts before the Lord's Supper were a common practice. (A Short History of the Baptists, Henry Vedder, Chap. 15)
In the church in which I was raised, the 10th article of decorum passed down from the old Mt. Carmel Church required a "majority present shall rule in all cases except in maters (sic) touching fellowship, when the voice of the church shall be unanimous." This meant that some matters were settled by majority vote, but that receiving and excluding members, etc. had to done with unanimity. This rule reigned in the church until 1934, when a majority bent on excluding a member voted that the unanimous rule "be done away with".*
The historic Sandy Creek Association of North Carolina took the consensus principle beyond the local congregation to their associational meetings. According to David Benedict, "It had been usual with them to do nothing in Associations, but by unanimity. If in any measure proposed, there was a single dissentient, they labored first by arguments to come to unanimous agreement; when arguments failed, they resorted to frequent prayer, in which all joined. When both these failed, they sometimes appointed the next day for fasting and prayer, and to strive to bring all to be of one mind."
These are just some brief historical points to cause you to consider that Baptists probably have not always done it the way you may think they have -- hopefully to begin to knock a little of the wind out of the old "we've always done it that way" argument. Next we will look at the more important New Testament considerations.
* Note: an attempt to rescind the "anti-unanimous rule" vote was mounted in 1937 with no success. Though one might assume the church would be able exclude many more members without a "unanimous rule", this actually had the opposite effect. Perhaps this exclusion by a majority adversely affected the moral authority of the church and resulted in a loss of respect for church discipline.