Defeats across the once solidly blue Rio Grande Valley. Shrinking margins in big Democratic cities like Houston and Dallas. Lost seats in the State House.

The drubbing that Texas Democrats took in the 2024 election was bad enough to leave any party stalwart feeling deflated. After all, a yearslong belief that demographic shifts, population growth and rapid urbanization had Democrats on the cusp of flipping the nation’s most populous Republican state was seemingly in tatters after November.

Yet the newly elected chair of the Democratic National Committee, Ken Martin, made Texas one of the first stops this week on his first swing through the country. And the message he carried was the opposite: Texas, the second-largest state, could still be a linchpin for the national party’s revival.

“The future of the Democratic Party runs through Texas,” Mr. Martin said in an interview in Houston, pointing to national shifts in population away from Democratic coastal strongholds and toward the South. “We are here right now to start laying down the foundation.”

Mr. Martin spoke on Wednesday between meetings with local Democratic activists — hearing about the need for year-round investments in campaign infrastructure — in the same Houston hotel where Senator Ted Cruz celebrated his re-election victory over a well-funded, well-regarded Democratic challenger, Colin Allred, just a few months earlier.