U.S. Rep. Sam Johnson (R-Plano) announced he would not seek re-election in 2018. Johnson won a special election for the House seat in 1991, succeeding former U.S. Rep. Steve Bartlett, who had been elected mayor of Dallas.

The district lies entirely within Collin Co. and includes all of Allen, McKinney, Melissa and the Collin Co. portions of Dallas, Frisco, Plano, Prosper and Richardson .This heavily Republican open seat is likely to be determined by the 2018 Republican primary (runoff) election.

Sen. Van Taylor

Sen. Van

Potential candidates include Sen. Van Taylor (R-Plano); Reps. Pat Fallon (R-Frisco), Jeff Leach (R-Plano), Scott Sanford (R-McKinney), Matt Shaheen (R-Plano) and Scott Turner (R-Frisco); Collin Co. Judge Keith Self, District Attorney Greg Willis and Co. Comm. Susan Fletcher; and Plano Mayor Harry LaRosiliere. Other Republicans are expected to express interest in the seat.

In statements, Taylor and Leach thanked Johnson for his service but made no mention of a race to succeed him. Taylor lost a race for Congress to former U.S. Rep. Chet Edwards (D-Waco) in 2006. Self told the Texas Tribune he would “certainly consider” the race. A retired Army officer, he was first elected Collin Co. Judge in 2006.

In a tweet, Carrollton Mayor Matthew Marchant warned “ambitious Collin County friends” that local officials should be wary of “resign-to-run” provisions of state law that could trigger automatic resignations from current offices. As county judge, Self would be required to resign immediately upon announcing his candidacy under Article XVI, Section 65 of the Texas Constitution.

Incidentally, Section 251.001, Election Code provides that the filing of campaign treasurer paperwork does not constitute announcing one’s candidacy, so an officeholder affected by resign-to-run laws may still raise money and explore candidacy without becoming a candidate.

Johnson received 75% of the vote in the 2016 Republican primary against three opponents and 81% in the 2014 Republican primary against three different opponents. He had otherwise received at least 83% of the vote in every Republican primary since 1992.

Taylor’s senate district almost perfectly aligns to Johnson’s congressional district. Of the 178 precincts in Johnson’s district, 151 are also in Taylor’s district. Taylor is up for re-election in 2018, so a run for Johnson’s seat would require Taylor to abandon his re-election bid, opening the seat to his former House colleagues and others. Any House member seeking Taylor’s potentially open seat would have to abandon their re-election bids to the House, opening their seats to other Collin Co. Republicans.

Self and Willis are also up for re-election in 2018, but the resign-to-run law would open their seats earlier if they chose to run for Johnson’s (or Taylor’s) seat. Fletcher was re-elected last year but also subject to the resign-to-run law. LaRosiliere is up for re-election in May.