Don Horn Challenges Incumbent Pat Fallon in Collin-Area GOP Primary

Don Horn has filed again to challenge incumbent U.S. Rep. Pat Fallon in the March 3, 2026 Republican primary for Texas' 4th Congressional District, a seat that includes parts of Collin County and stretches into counties along the Red River and sections of the suburban and exurban DFW Metroplex. In the March 5, 2024 Republican primary, Fallon received 70,801 votes (80.3%) to Horn’s 17,396 votes (19.7%), setting up a clear numerical baseline for this rematch.

Fallon remains the district incumbent, having been described as re-elected with 68.4% of the vote in 2024. The district’s geography - combining Red River counties with fast-growing Collin County suburbs - has shaped recent electoral margins and will be central to both campaigns as they court primary voters across divergent precincts.

Horn’s background includes service in the U.S. Navy and bachelor’s degrees in religion and sociology from California Baptist College; his career experience listed in filings and candidate materials spans social work, landscaping, and welding. He was described in earlier coverage as a farmer and a 2024 candidate for the seat, underscoring the rural-exurban profile he emphasizes to voters in Collin-area precincts.

The March 3 primary ballot currently lists Pat Fallon and Don Horn for the Republican contest and a field of Democratic candidates including Andrew L. Rubell and Jason Pearce; county election listings additionally show Brice Gonzales among Democrats who have appeared on local ballots. Election filings and candidate lists for the 2026 cycle include a caveat that candidate rosters may not be complete, so final certified ballots should be verified with county election offices.

Local voter guidance underscores the role of the March primary in determining November ballot choices. Denton County election guidance notes that primaries determine which party nominees will appear on the following Nov. 3 general election ballot and directs voters to consult county election resources to confirm registration status and view sample ballots ahead of March 3.

A recent candidate questionnaire published Feb. 19 included separate sections for Fallon and Horn and invited readers to hear from the candidates who answered that questionnaire ahead of the primary. That Q&A format gives area voters a side-by-side look at positions ahead of early voting and Election Day.

With the rematch framed by the 2024 primary tallies - Fallon 70,801 to Horn 17,396 - the outcome in Collin County precincts and adjacent exurban precincts will be decisive for the Republican nomination on March 3, 2026. Voters should check their county election office for the most current ballot and registration information.