AUSTIN - Amarillo businessman Tom Mechler resigned as chairman of the Republican Party of Texas on Saturday, citing the job's long-term strains on his family life.

In a letter to party leaders, Mechler said his two-year tenure as chairman has been marked by personal financial difficulties that affected his family's well-being and by travel that took him away from home about 80 percent of the time.

"With fluctuations in the oil industry, my family struggled to financially stay afloat," he wrote, adding that he had to sell equipment to keep his business in the black. "While we were making great strides in our party, my family was suffering. These past two years have been a whirlwind of activity and success, but they've also been a series of absences."

The State Republican Executive Committee will select an interim chairman to fulfill the remainder of Mechler's term at its June 3 quarterly meeting in Austin. The term ends at the state party's 2020 convention, when delegates will elect a new chairman.

In his letter, Mechler lamented recent internal fights that increasingly have split Republican voters and their elected leaders into two camps: a tea party-aligned group that seeks to purge what they see as too-moderate Republicans, and those who favor a more traditional GOP model aligned with business interests.

"It is no secret that our party is divided into factions. It is also no secret that those factions frequently throw rocks at each other," he wrote. "As I prepare to leave this role, my hope is that every faction of this party will treat each other with kindness and respect."

He also included a stern warning to Texas Republicans that the state's changing demographics could doom the party - which has had complete control of state government for more than two decades - if it does not address issues of diversity within its ranks.

"Our state will soon have a majority-minority voting age population," he wrote, encouraging the committee to replace him with someone who will make minority outreach a priority. "If we do not continue to make efforts to engage in the diverse communities across Texas, our state will turn blue. This is no longer just a possibility; it is an inevitable reality if we fail to act."

Mechler became interim chairman after his predecessor, Steve Munisteri, left the leadership post in 2015 to join the presidential campaign of Kentucky Sen. Rand Paul. During the party's 2016 convention last May, Mechler easily defeated Houston lawyer Jared Woodfill, a far-right Republican who painted Mechler as too moderate to lead the country's most prominent state GOP, to win the chairmanship in his own right.