Why are migrants in the US being sent to Democrat-run areas?

Venezuelan migrants were recently sent from Texas to just outside Vice-President Kamala Harris' residence

Thousands of migrants have been sent from Republican-led states to Democratic-run areas as part of a growing row with the federal government and the Biden administration.

Two buses carrying people primarily from Venezuela were recently left outside Vice-President Kamala Harris' residence in Washington DC. Texas Governor Greg Abbott, who approved the move, then called for tighter immigration policies.

The night before, Florida took credit for sending two planes carrying migrants to the wealthy enclave of Martha's Vineyard in Massachusetts, an apparent escalation of a tactic that has also already seen migrants taken to Chicago and New York.

While opponents of the tactic have described it as cruel and inhumane, three state governments insist it is a result of the Biden administration's own border policies.

Why are the migrants being moved?

Three states - Texas, Arizona and Florida - have announced initiatives to move migrants to Democratic-led ones, which they have accused of being "sanctuary" jurisdictions that fail to enforce immigration laws.

Officials in those states say the tactic is aimed at mitigating the impact of migration flows in local communities.

They have also said the measure is designed to increase pressure on the Biden administration to do more to reduce the number of people crossing the US-Mexico border, which has hit a record high this year.

In a letter instructing local authorities to begin carrying out the initiative, Governor Abbott argued that the federal government had "no real plan" for addressing an unprecedented "surge of illegal aliens" that might otherwise find themselves in Texan cities.

"Texans cannot continue to shoulder the burdens imposed by open-border advocates in other parts of the country," he wrote.

How many have travelled?

According to statistics compiled by the BBC's US partner CBS, as of 16 September Texas and Arizona had sent almost 300 buses carrying approximately 13,000 migrants to Washington DC, New York and Chicago.

The bulk of these people were sent from Texas, which has spent $12m (£10.5m) to finance the journeys. Arizona has spent about $4m.

While we know Florida's state legislature has appropriated $12m to transport migrants, the exact details of its relocation programme remain unclear.

The BBC has reached out to state officials for comment.

Is bussing migrants legal?

While experts expect that the relocation of migrants will be legally challenged, at the moment it is still unclear what - if any - laws may have been broken. Federal prosecutors and officials are reportedly weighing a range of legal options.

Some - including Chicago Mayor Lori Lightfoot - have suggested that the migrants are being "misled" about the trips. Others have even compared the process to kidnapping and people smuggling.

State officials, however, insist that the migrants are going willingly, and in Texas' case say they have signed a voluntary waiver.

Buses carrying migrants arrive in New York City in late August

Some of the migrants who arrived in Martha's Vineyard told reporters that they were promised work, assistance and expedited paperwork. They also thanked Florida's governor for having sent them to the wealthy enclave, according to US media.

"The big question is what they are being told, and if there is any sort of fraud or inducement," immigration lawyer Aleksander Cuic, the director of the Immigration Clinic at Case Western Reserve University, told the BBC. "But how would anyone know if there's nothing in writing?"

Mr Cuic added that the states will probably argue they are merely doing what the federal government does all the time - moving detained migrants around the country.

Why are they choosing to go?

According to Adam Isacson, a migration and border expert from the Washington Office on Latin America, many would have ultimately left Texas and the other Republican states anyway.

"You've had migrants coming to all these cities in huge numbers in the past, but they always paid for it themselves," he said. "You've always had tens of thousands of migrants coming to New York City from the border, for example."

Several people who had travelled on these buses told the BBC they were informed of where they were going - and that in some ways, a bus north from Texas was the best available option.

"I could have stayed on the streets [in Texas] or come on the bus. So I came," Darling Vielma, an 18-year-old Venezuelan travelling with two children, said after she was brought to Washington DC in early September. "There was nobody for me in Texas."

Similarly, migrants in Texas said they were willing to be transported to other states - and were told where they'd potentially be going - but that officials told them that women and children were being given priority.

Several said they would prefer to be sent out of state than have to remain in Texas, far from family and without shelter.

"I've got to take the opportunity if offered," one man said on Thursday. "Or I'll be out on the street."

What does this mean for US politics?

Mr Isacson described this tactic as "political theatre".

"There are six or seven weeks until the midterms, and Republicans are starting to slip in the polls," he said. "[They] are sort of creating their own [migrant] caravan. It's something that their base can get excited about."

The tactic has already led to an escalating war of words between the White House and the Republican state governors.

President Biden, for example, has accused the governors of "playing politics with human beings" and "using them as props".

The Republicans, in turn, have laid the blame squarely at Mr Biden's feet and derided the Democrats as not doing enough to stop migrants from crossing the border in the first place.

"The minute even a small fraction of what those border towns deal with every day is brought to their front door, they [Democrats] all of a sudden go berserk," Governor DeSantis said.

(With additional reporting from Lioman Lima in Washington and Angelica Casas in Texas)