Drew was first elected in 2006 to serve the people of House District 72 in the Texas House of Representatives. Drew is a lifelong West Texan, San Angelo native, and a product of San Angelo public schools. Representative Darby graduated from the University of Texas at Austin with a Bachelor of Business Administration, majoring in Finance and minoring in Accounting. He earned a Doctorate of Jurisprudence from the University of Texas in 1971, and is a graduate of the Emerging Political Leaders Program at the Darden School of Business, University of Virginia.

Representative Darby currently serves as chairman of the House Committee on Redistricting and as a member of the House Committee on Criminal Jurisprudence and the House Committee on Energy Resources. Additionally, Representative Darby serves as Vice-Chair of The Energy Council, and is the Texas House's appointee to the Southern States Energy Board.

In previous legislative sessions, Drew has served as a member of the Legislative Budget Board, the State Water Implementation Fund for Texas Advisory Committee, as a subcommittee chairman for the House Committee on Appropriations, and as a member of the Royalty Policy Committee of the United States Department of the Interior.

A successful businessman, Drew is the owner of Surety Title with offices throughout West Texas, and is Of Counsel to the Energy and Real Estate practice group at the law firm of Jackson Walker, LLP.

Drew's leadership positions have been as a member of the San Angelo City Council, former chairman of the San Angelo Water Advisory Board, and chairman of the Lake Nasworthy Advisory Board.

Drew and his wife, Clarisa, have five children and eleven grandchildren. They are members of the First Presbyterian Church of San Angelo.