Incumbent Thomas Massie Maintains Slight Lead Over Challenger Ed Gallrein, Though Spending Took a Toll
The Kentucky House District 4 Republican Primary Tracking Poll for Friday May 15 finds Thomas Massie with a slight edge over Ed Gallrein, 50.6% to 49.4%. The survey was conducted by BIG DATA POLL as part of the Public Polling Project and will update until Election Day.
“The Republican primary for the U.S. House in Kentucky’s Fourth Congressional District looks like a race as close as the Kentucky Derby,” BIG DATA POLL Director Rich Baris, said in a statement. “The race has tightened, but that’s almost entirely due to increased turnout projections for voters over the age of 45.”
“Historically, voters under the age of 45 vote at higher rates than we currently project and early voting seems to indicate that might be the case, which would bode well for the incumbent given this race is a generational battle.”
“It’s a cliche, but it really is all about who decides to vote on and before Tuesday.”
Rep. Massie is leading with Gen Z (81.5% to 18.5%), Millennials (68.6% to 31.4%) and Gen X (53.0% to 47.0%), while Mr. Gallrein leads with Boomers/Silent Gen (62.0% to 38.0%). Interestingly, Mr. Gallrein’s lead among those 65+ actually narrowed from 65.0% to 35.0% last month to 61.1% to 38.9%.
Last month, Rep. Massie led 52.4% to 47.6%, with undecided voters breaking his way 57.5% to 42.5%. As of Friday, undecideds were breaking to the incumbent 52.1% to 47.9%.
The incumbent Republican is being challenged by President Donald J. Trump and allies in The American Israel Public Affairs Committee (AIPAC) and pro-Israel lobby has backed Mr. Gallrein now to the tune of nearly $12 million, or $11,824,741.
The Kentucky House District 4 Republican Primary Tracking Poll will be updated daily until Election Day and will reflect early vote totals. The poll finds Rep. Massie leads with those who plan to vote early no-excuse 57.6% to 42.4%, while Mr. Gallrein leads with in-person Election Day voters 52.3% to 47.7%.
Methodology
The Public Polling Project conducted by BIG DATA POLL interviewed 518 Registered Republican likely primary voters districtwide from May 12 to May 14, 2026. Interviews conducted online (≈10%) are sourced through Lucid (CINT) and live-agent phone interviews including P2P SMS and text-to-online are sourced from either the L2 National Voter File Database. Participants who opted for text-to-online were given 24 hours to complete the interview. Interview details plotted on maps can be reviewed by hovering and clicking on the locator pins. Results were weighted for sex, age, race, education, region and geography. The weighting efficiency was 98.6%. The overall sampling error is ±4.0% at a 95% confidence level. It is important to note that sampling errors for subgroups are higher. All BIG DATA POLL publicly conducted surveys are crowdfunded via the Public Polling Project, supplemented if necessary by BIG DATA POLL and are NOT funded by or affiliated with any candidate, campaign, committee, or political entity. Full and interactive crosstabs for Friday, May 15, 2026 can be viewed on MarketSight.
