Sen. Ted Cruz, R-Texas, said in a new attack ad that his Democratic challenger, Rep. Beto O’Rourke, voted against a bill that helped hurricane victims pay lower taxes.

The spot, released Tuesday, also credits the freshman senator for securing federal aid dollars that Congress sent to the Lone Star State in the wake of the devastating hurricane that hit southeastern Texas in August 2017. The ad also suggests that O'Rourke, a congressman from El Paso who recently appeared within striking distance of Cruz's Senate seat in an NBC News/Marist poll, opposed helping his fellow Texans.

Are Cruz's claims in the ad accurate?

Did O'Rourke vote against Harvey aid?

“Congressman Beto O’Rourke? So irresponsible that he even voted against Hurricane Harvey tax relief," the ad says.

It's true O'Rourke voted against a tax relief bill, though the claim leaves out the fact that O'Rourke did vote for several other bills that provided Harvey aid to Texans. O'Rourke voted against one bill — H.R.3823, the Disaster Tax Relief and Airport and Airway Extension Act of 2017 — that contained tax breaks for victims of the hurricanes Harvey, Irma, and Maria.

In Austin on Wednesday, O'Rourke defended his decision, saying he'd "voted for more than $90 billion in aid for Hurricane Harvey victims" and the bill Cruz is highlighting just wasn't a good deal for victims.

O'Rourke also explained his vote on his blog.

"The bill provided help in the form of tax breaks at a much lower rate than those provided to victims of both Hurricane Sandy and Hurricane Katrina," he wrote at the time of his initial nay vote.

"The claim that he voted against the bill because there wasn't as much relief as Sandy victims received must be an attempt to mask the complete ridiculousness of his vote. In fact, there was no similar provisions enacted for Sandy," a Cruz campaign spokesman said in response.

Hurricane Sandy victims were not given such tax cuts, and lawmakers from New York and New Jersey, the states hit the hardest by the hurricane, sought to get their constituents included in the legislation. Hurricane Katrina victims did get tax cuts.

A spokesman from O'Rourke's campaign emailed after this article was published to add that his initial blog post should have referred to Hurricanes Katrina, Rita and Wilma, but not Sandy.

"Beto voted against legislation (HR 3823) that shortchanged Harvey victims by providing fewer tax breaks than those provided after Hurricane Katrina, Hurricane Rita, and Hurricane Wilma, even though Harvey produced the greatest amount of rain ever recorded in the continental U.S.," the spokesman noted.

Responding to the Cruz ad on Wednesday, O’Rourke’s campaign pointed to four House bills with Harvey relief that O'Rourke did vote for — three of which became law — and Cruz's own recent record on disaster relief.

We checked into that, too.

Cruz's own votes against disaster relief

"When disaster struck, Texans came together. Helping each other. Everyone doing their part. Like Ted Cruz, who brought home billions in disaster relief, and passed bipartisan emergency tax relief for those hit by Hurricane Harvey," the ad says

That's true: Cruz did help advocate for billions in disaster relief. Though Sen. John Cornyn, R-Texas, lead the effort, he said the freshman senator was "indispensable" in securing resources.

O'Rourke's camp, however, points to Cruz's vote against a 2018 omnibus spending bill that included more than $7 billion that was earmarked to replenish the Federal Emergency Management Agency’s disaster relief fund.

When Cruz voted against the $1.3 trillion spending bill, he said it was "drafted by the swamp in the dark of night" and that it would "plunge our nation even deeper into debt."

Asked about that vote, a Cruz campaign spokesperson pointed to the Harvey funding, listing off four separate funding bills the senator had supported — three of which had passed with O'Rourke's vote, too.

It's worth going a bit deeper into Cruz's history, however.

Cruz's recent ad against O'Rourke touts that the Harvey relief bills were bipartisan, and that's true. Federal aid packages for natural disasters almost always earn broad and bipartisan support as lawmakers tend to abandon budget feuds over disasters, perhaps because their districts could need relief in the future.

Cruz, however, is one of the few lawmakers who has made disaster aid a partisan issue in the past.

In 2012, the Texas senator declined to support hurricane relief funds for New York and New Jersey after Hurricane Sandy. Cruz defended his "no" votes by saying the bill was “filled with unrelated pork,” a claim other fact checkers declared to be false.