It's not just Democratic-leaning states at risk of losing federal money and clout in Congress if the Supreme Court says the upcoming census can include a citizenship question.
Fast-growing Arizona, Florida and Texas all have large groups of immigrants, especially Hispanics, who might choose to sit out the census, but are led by Republicans who seem unconcerned about the potential for an undercount and the resulting loss of representation in Congress.
The divide between blue and red states with large immigrant populations is stark as both prepare for a census that could ask about citizenship for the first time in 70 years.
Republican lawmakers in several states with large immigrant populations praised the Trump administration for fighting to include the question and wondered whether immigrants should even be included in the count.
Florida state Sen. Joe Gruters, who also is chairman of the state Republican Party, said he wasn't worried about the potential consequences of an undercount.
"I don't care," he said. "It's the right decision, and I fully support the president and what he's trying to do."
He expects Florida will still pick up at least one seat because of rapid growth.
The U.S. Supreme Court will decide soon whether to uphold the Trump administration's plan to ask about citizenship on census forms. There appeared to be a clear divide between the court's liberal and conservative justices in arguments in the case this past week, with conservatives holding a 5-4 majority.
Federal law requires people to complete the census accurately and fully. But Ceridwen Cherry, a lawyer on the American Civil Liberties Union's voting rights project, said including a citizenship question could contaminate the form for many people and result in an undercount.
"If a citizenship question is added, immigrants and those who live in households that contain noncitizens are going to be more likely to not respond to the census at all," she said, "or respond and leave off noncitizens from the form."
The concern among certain immigrant groups — particularly Hispanics and Muslims — is driven by the Trump administration's oftentimes harsh rhetoric about immigration and fears that it will share the census data with immigration authorities. When an advisory committee asked the U.S. Census Bureau about that worry last year, officials responded by saying that breaking census confidentiality is a federal crime punishable by up to five years in prison.
Opponents of the citizenship question point to a study by George Washington University political scientist Chris Warshaw, who found that two or three states are likely to end up with fewer congressional seats than they otherwise would have because of a citizenship question. The most likely in that category are Arizona, California, Florida, Illinois, New York and Texas.
On the other side, he said a citizenship question would make it more likely for Idaho or Montana to gain a seat and Minnesota or Ohio to avoid losing one. Nine states would have lost population since the last census if not for international immigration, according to an Associated Press analysis of a Census Bureau population estimate.
In Michigan, a political swing state, the concern is that it could discourage participation among the large Arab American community.
Hassan Jaber, a former census advisory board member, is critical of the administration's citizenship question and of a decision against adding a Middle East-North Africa classification to the 2020 census.
He said including the citizenship question could affect federal funding for programs and services related to food, health and education. But he's more troubled by the message it sends to Arab Americans and others.
"The Trump administration's effort to suppress this recognition of this community sends signals of being unwelcome and to politicize the census ... and turn it against minority groups," said Jaber, CEO of ACCESS, a Detroit-area social services organization. "It's really something that becomes much bigger than just the data on Arab Americans."
Matt Barreto, a UCLA professor who submitted testimony in court cases about the citizenship question, did polling that showed 7.1% to 9.7% of the population might skip the census if it's added. He also found that nearly half of Californians don't trust the Trump administration to keep the citizenship information out of the hands of other government agencies.
"The administration wanted a citizenship question to hurt California. In the end, they're going to end up hurting conservative states and counties," said Ali Noorani, executive director of the National Immigration Forum.
Conservatives generally support adding the citizenship question, even if it might suppress the total population count in their state.
"If we would be entitled to another congressional seat, the question is, should we be entitled to it because we have more non-citizens living here that are not voters, or shouldn't be voters?" said Arizona Senate President Karen Fann.
Arizona Republican lawmaker John Fillmore said he's not concerned about the fallout. He said he believes the state's explosive growth will ensure it doesn't lose clout.
"I do not believe Arizona's going to lose a House seat in any way shape or form," he said.
In Texas, Republican state Rep. Phil King said there is bipartisan agreement that everyone should be counted. He said the state is likely to pick up seats in Congress because of its rapid population growth, but it will be a close call to determine how many.
"What we've got to do as a state is just make sure that we have programs in place that strongly encourage everybody to respond to the census and to know that it's safe and OK to do that," said King, who is chairman of the House redistricting committee.
Texas Civil Rights Project spokesman Zenen Jaimes Perez said the organization has not had any coordination with the state on making sure Hispanic communities are counted. Perez said the group has worked with city officials in Austin, Houston and San Antonio to host community forums about the census and the importance of filling it out.
Census data is used to divide the 435 U.S. House seats between 50 states and determine their clout in the Electoral College. It's also used to draw state legislative district maps and divvy up federal funding to states, cities and counties.
About half the states have created "complete count" commissions to coordinate grassroots efforts designed to convince people to complete their census forms, according to the National Conference of State Legislatures.
Republican Gov. Doug Ducey of Arizona, who supports the citizenship question on the census, this month created a complete count committee to work on outreach.
He said the state stands to lose an estimated $887 in federal funding each year for every person who skips the count.
Ducey said the group will include people with expertise in reaching out to rural areas, tribes, universities, apartment dwellers, faith organizations, veterans and community organizations. Lawmakers are considering spending $5 million on the effort, a proposal that cleared the Senate nearly unanimously.
Ducey told Capitol Media Services earlier this month that asking about citizenship is "a fair question" to "get a handle of who's here, who's a citizen and who's not."
His spokesman, Patrick Ptak, declined to comment on the prospect of not gaining a House seat but said the census is a priority for the governor's office.
Persuading people to respond to the Census requires explaining how it's linked to funding for schools, hospitals and other services — and making them know it would be illegal for the census to share individual information, said Vanita Gupta, president and CEO of The Leadership Conference on Civil and Human Rights.
"An army of lawyers will be ready in the worst-case scenario that there is some kind of nefarious action taken around census confidentiality," Gupta said.
Associated Press writers Brendan Farrington, Jeff Karoub and Clarice Silber contributed to this report.