Cornyn, the Republican incumbent, and Democratic challenger Alameel will debate before an Internet, cable television and Spanish-language television audience Friday at 7 p.m. Central time. The debate will be streamed live on the Texas Tribune website and carried on a two-hour delay on C-SPAN and a three-hour delay in Spanish on Univision television stations in Austin, Corpus Christi, Dallas-Fort Worth, El Paso, Laredo, McAllen, Midland-Odessa and San Antonio.