2012 Texas House of Representatives election

Following the 2010 United States census, the Texas Legislature underwent its decennial redistricting. Due to Texas's shifting population from rural and urban areas to suburban areas, many rural representatives became vulnerable to having their districts moved across the state. Although Republicans had ousted almost every Democrat representing rural Texas in the 2010 elections, those gains were temporary, as many of the regions they won had lost population over the last decade. As such, it was seen as unlikely that Republicans would be able to draw maps that would allow them to maintain their supermajority in the chamber after the 2012 elections, despite their full control over the redistricting process.^[3]

Texas House of Representatives districts follow the "county line rule," effectively granting individual counties delegations of state house seats based on their population.^[4] The census found that Texas had a population of 25,145,561 in 2010,^[5] giving each district an "ideal population" of 167,637 people. In 2000, the "ideal population for a district" was 139,006 people. Counties with at least this number of people must fully contain at least one state house district. Counties with sufficient population for two or more districts must be divided into that number of districts. Should a county have sufficient population for one or more district plus a fraction of another, one district from another county may extend into it to represent the remaining population. District delegations for counties with at least one district changed as follows following the 2010 Census:^[6]

County	2000 pop.[7]	Seats	Partial	2010 pop.[7]	Seats	Partial	+/– W	+/– P
Bell County	238,000	1	Yes	310,235	1	Yes
Bexar County	1,393,035	10	No	1,714,773	10	No
Brazoria County	241,805	1	Yes	313,166	1	Yes
Brazos County	152,436	1	Yes	194,851	1	Yes
Cameron County	334,884	2	Yes	406,220	2	Yes
Collin County	491,272	3	Yes	782,341	4	Yes	1
Dallas County	2,216,808	16	No	2,368,139	14	No	2
Denton County	433,065	3	No	662,614	4	No	1
El Paso County	679,568	5	No	800,647	5	No
Fort Bend County	354,286	2	Yes	585,375	3	Yes	1
Galveston County	250,178	1	Yes	291,309	1	Yes
Harris County	3,401,139	25	No	4,092,459	24	No	1
Hidalgo County	569,099	4	No	774,769	4	Yes
Jefferson County	251,968	1	Yes	252,273	1	Yes
Lubbock County	242,644	1	Yes	278,831	1	Yes
McLennan County	213,525	1	Yes	234,906	1	Yes
Montgomery County	293,779	2	Yes	455,746	2	Yes
Nueces County	313,512	2	Yes	340,223	2	No
Smith County	174,861	1	Yes	209,714	1	Yes
Tarrant County	1,449,290	10	No	1,809,034	11	No	1
Travis County	811,776	6	No	1,024,266	6	No
Webb County	193,124	1	Yes	250,304	1	Yes
Williamson County	250,466	1	Yes	422,679	2	Yes	1

As a result of these changes, the following districts drastically moved:

1. District 33 moved from Nueces County to Collin County.
2. District 35 moved from South Texas to Hidalgo County.
3. District 85 moved from West Texas to Fort Bend County.
4. District 101 moved from Dallas County to Tarrant County.
5. District 106 moved from Dallas County to Denton County.
6. District 136 moved from Harris County to Williamson County.

Summary of the November 6, 2012 Texas House of Representatives election results

Party		Candi- dates	Votes	%	Seats	+/–
	Republican Party	117	4,237,987	62.37%	95	7
	Democratic Party	86	2,272,530	33.45%	55	7
	Libertarian Party	38	230,008	3.9%	0	–
	Green Party	13	53,189	0.78%	0	–
	Write-in	1	715	0.01%	0	–
Total			6,794,519	100.00%	150	–

Seats where the margin of victory was under 10%:

District 43: Representative J.M. Lozano (D-Kingsville) was re-elected as a Democrat in 2010 with 77.90% of the vote. On March 5, 2012, he announced that he would switch parties and seek re-election as a Republican.^[8] He would later go on to narrowly win re-election in 2012 with 51.55% of the vote.