Example from Wikipedia:
To show the calculation of a state's delegation, the following example shows the size of the Texas delegation (based on the current political makeup and not counting additional delegates due to the intervening Census; Texas is a GOP stronghold):
Texas is allowed 10 delegates under the at-large rule.
The chairperson of the Texas GOP, the state national committeeman, and the state national committeewoman counts as one delegate each, for a total of three delegates.
Texas will have 36 members in the House of Representatives after the 2012 elections; thus, Texas is allowed 108 delegates (36 * 3) under the House membership rule.
As John McCain carried Texas in the 2008 United States Presidential Election, and as Texas has 38 electors (36 House members plus its two Senators), Texas is allowed 4.5 delegates under the at-large provision plus an additional 22.8 delegates (38 * 60%), for a total of 27.3 (4.5 + 22.8), rounded upward to 28 delegates.
Texas is allowed the following additional delegates as follows:
One additional delegate as the current Governor of Texas (Rick Perry) is Republican.
Of the 32 current members of the House, 20 are Republicans; thus, one additional delegate under this provision.
As both houses of the Texas Legislature are controlled by the GOP (77-73 in the Texas House of Representatives and 19-12 in the Texas Senate) and both chambers are presided over by a Republican (Joe Straus as the Speaker of the House and David Dewhurst as Lieutenant Governor, which presides over the Senate), two additional delegates (one for having any chamber meeting the criteria, and one additional for having both chambers meet the criteria).
As both United States Senators from Texas are Republicans (Kay Bailey Hutchison and John Cornyn), and as both have been elected within the past six years, two additional delegates.
The Texas delegation would thus consist of 10 + 3 + 108 + 28 + 1 + 1 + 2 + 2 = 155 members.