Ted Cruz, a US senator from Texas, faced criticism for flying to Mexico on Wednesday after his home state was battered by historic winter storms.
He returned to Houston on Thursday night after reportedly moving up his flight following a public outcry over his apparent neglect of the humanitarian crisis.
Mr Cruz defended the trip, saying it was for his daughters.
"With school cancelled for the week, our girls asked to take a trip with friends," he said through his office on Thursday afternoon.
"Wanting to be a good dad, I flew down with them [to Cancun] last night and am flying back this afternoon.”
Images started circulating on Wednesday evening showing Mr Cruz at Houston’s Bush Intercontinental Airport boarding a flight to Cancun.
United flight UA1020 departed Houston for Cancun at 4.44pm, exactly 34 minutes after the photos were posted, an ABC local affiliate channel reported.
Millions of Texans are without power and heat as snow and ice storms ravage the state. At least 10 people died.
"My staff and I are in constant communication with state and local leaders to get to the bottom of what happened in Texas," Mr Cruz said on Thursday.
Former MSNBC host David Shuster on Wednesday night tweeted another photo showing Mr Cruz on the flight.
Mr Shuster said Mr Cruz and his family “flew to Cancun tonight for a few days at a resort they've visited before”.
The temperature in Cancun is expected to reach a high of 29°C on Thursday. Temperatures in some areas of his home state fell to minus 12°C this week.
AP confirmed the trip with a source who said the family holiday had been planned for a long time.
Many took to Twitter to criticise the senator, showing food lines and images of Texans lined up for groceries.
"We want our power back, our water on, and our homes warm," Mr Cruz said.
"My team and I will continue using all our resources to keep Texans informed and safe."
The Texas Democratic Party called on Mr Cruz to resign.
“Texas, you deserve so much better. Upgrade your representation starting in '22!” Democratic National Committee chairman Jaime Harrison tweeted.
A Thursday flight from Cancun to Houston listed the name Cruz among those on standby for a seating upgrade.
ABC reported on Thursday that the senator's staff contacted the Houston Police Department to offer assistance on his return to the state.
The aviation news website Skift reported that Mr Cruz had rebooked his ticket on United airlines today at 6am, moving his departure up by two days.
Mr Cruz was seen boarding alone in the Cancun airport without his family, pulling a black suitcase.
He is expected to land in Houston at 4.05pm local time.
Social media focus on his flight travel is a reminder of other flights that have caught public attention over the past decade.
It pales in comparison with British politician Priti Patel's return flight to the UK from Kenya in 2017 after it was rumoured that she would be fired from the Cabinet.
Former prime minister David Cameron was also criticised for going on holiday in Ibiza a short time after his country suffered terrorist attacks in 2013.
There was also the 2013 flight from South Africa to New York that carried Justine Sacco, a public relations staffer at media company IAC at the time, who tweeted a racist remark before departing.
The post led to her firing after her tweet went viral on social media with the hashtag #HasJustineLandedYet.
