"Dirty Thirty" was the name given to thirty members of the 1971 Texas House of Representatives who grouped against Speaker of the House Gus Mutscher and other Texas officials charged in a bribery-conspiracy investigation by the United States Securities and Exchange Commission. The coalition of thirty Democrats and Republicans, conservatives and liberals, has been given credit for keeping the Sharpstown Stock Fraud Scandal alive as a political issue. One member called for a resolution to make Mutscher and his associates resign from leadership positions while the SEC investigation continued, but Mutscher was still favored by a majority in the House, and the measure failed. Another resolution, for the House to make itself a committee of the whole to study the SEC allegation, also failed. The criticism by the Dirty Thirty of Mutscher's system of controlling legislation led him, finally, to agree to an investigation. But he appointed five of his closest House allies, all chairmen of other committees he had appointed, to do the job. This blatant use of appointive power to clear himself actually helped the Dirty Thirty's cause. On the next-to-last day of the session, Mutscher attacked the group, accusing them of irresponsible and partisan politics. In return the group called Mutscher a dictator of state politics, more concerned with private than public interests. This began the electoral battle, which Mutscher lost.
In September 1971 a Travis County grand jury indicted Mutscher and two colleagues for conspiracy to accept a bribe and accepting a bribe. It also strongly recommended reform in the power of the speaker, although this recommendation was largely ignored; in 1993 minor reforms occurred. Mutscher was tried, found guilty, and sentenced to five years' probation. Although not brought to trial, Governor Preston Smith and Lieutenant Governor Ben Barnes saw their political careers effectively ended. The Dirty Thirty paid a price, also, for Mutscher blocked most of the legislation introduced by the members, and they found themselves isolated from other legislators.