Bob Marshall vs Nate Marsh: Highlands Ranch's House District 43, the Closest Legislative Seat in Douglas County

If you live in Highlands Ranch, the most competitive race on your ballot is not for Congress or governor. It is for a seat in the state House that has been decided by 400 votes and then by 1,373, held by the first Democrat Douglas County has sent to the legislature since 1966, and now contested by a prosecutor from the county DA's office.

Bob Marshall, Democrat

Marshall grew up in Evergreen, went to Georgetown and Cornell Law, and spent 26 years in the Marine Corps, retiring as a lieutenant colonel in 2017 after service that included Iraq and Afghanistan and a tour as a station judge advocate in Japan. He clerked on a federal appeals court and worked as a tax attorney at the IRS. He was a registered Republican for more than 30 years, left the party in 2017 over Donald Trump, sat unaffiliated for four years, and registered as a Democrat in 2021.

Before he ran for anything, he sued the Douglas County school board over open-meetings violations in the firing of the superintendent, and won. After he was elected, he sued the leadership of his own chamber, of both parties, over closed-door practices at the Capitol; that suit settled in 2023 with changes to how the House does business. This year he sued the county commissioners over the fiscal note they attached to Question 200 and their addition of Question 1A. He lost the injunction. Judge Klingensmith remarked from the bench that 1A's wording "doesn't track that language" in the statute while stressing the court was "not making a judgment" on it; the ruling did not decide whether the wording complied with state law (our account). Transparency litigation is not a side project for Marshall; it is most of his political identity.

In the House he sits on Finance and Judiciary. His campaign points to a record of bills passing with bipartisan votes. On guns his record is not a party-line one: when the House passed HB24-1292, the 2024 assault-weapons ban, on third reading on April 14, 2024, Marshall was one of nine Democrats who voted no. The bill cleared the chamber 35 to 27 without him.

Nate Marsh, Republican

Marsh grew up in Montana, moved to Highlands Ranch in middle school, and holds a political science degree from TCU and a law degree from the University of Maryland. He worked economic-crime cases in the Baltimore City State's Attorney's Office during law school, then came home to prosecute in Colorado, where his caseload has run from DUIs to first-degree murder. Since 2021 he has been in the DA's Family Violence Unit prosecuting domestic violence cases; earlier his caseload specialized in sexual offenses against children. He is now a senior deputy district attorney. The Colorado District Attorneys' Council named him a faculty member of the year for training other prosecutors.

His platform is a prosecutor's: eliminate mandatory cashless bail for certain crimes, guarantee prison time for violent offenders, reform the competency system, and back law enforcement. On money, he wants fewer of what he counts as Colorado's 165,000-plus regulations, lower taxes and an end to hidden fees. His third plank is parental rights, framed as stopping government and school interference. He is endorsed by the Fraternal Order of Police Lodge 47, the Colorado State FOP, the Colorado Chamber, NFIB Colorado and John Kellner, among others. He has said publicly that HD-43 is "one of the most winnable seats" for Republicans this year, and on the numbers he is right.

One thing worth knowing about the matchup: Marsh works for District Attorney George Brauchler, the county's most prominent Republican officeholder, whose office is currently suing the state over immigration law. Marshall, in the same weeks, is suing the county. The two candidates are, in a real sense, proxies for the two governments that keep taking each other to court.

The math

Highlands Ranch is the part of Douglas County that has moved fastest toward the middle. Marshall's 2022 win, by roughly 400 votes over a Republican incumbent, was the first time a Democrat had won a Douglas County legislative seat in 56 years. His 2024 margin, 1,373 votes (27,915 to 26,542) in a presidential year that was good for Republicans in the county, was wider but still only 2.5 points. Two-year House terms mean he has to do it a third time, in a midterm.

The midterm cuts both ways. Turnout falls and skews older and more Republican than a presidential year, which helps Marsh. But midterms historically punish the party in the White House, which in 2026 is the Republicans, which helps Marshall. And Marshall has a new argument that did not exist in 2024: he is the person who fought the county's own commissioners over the ballot, in a community that just petitioned by the tens of thousands to expand that board. Whether Highlands Ranch voters read that as a public servant or a litigious gadfly is, more or less, the election.

What to watch

Money, when the October reports post. Whether Marsh runs on Brauchler's office or away from it. And the top of the ticket: if Victor Marx and Lauren Boebert run behind a generic Republican in Highlands Ranch, Marsh needs ticket-splitters to get back to even.

More: every race on your ballot and the full ballot guide. We do not endorse candidates. Campaigns can send corrections to hello@discoverdougco.com.