Trump administration officials have proposed transporting detained immigrants to sanctuary cities at least twice in the past six months — once in November, as a migrant caravan approached the U.S. southern border, and again in February, amid a standoff with Democrats over funding for Trump’s border wall.

House Speaker Nancy Pelosi’s district in San Francisco was among those the White House wanted to target, according to DHS officials. The administration also considered releasing detainees in other Democratic strongholds.

White House officials first broached the plan in a Nov. 16 email, asking officials at several agencies whether members of the caravan could be arrested at the border and then bused “to small- and mid-sized sanctuary cities,” places where local authorities have refused to hand over illegal immigrants for deportation.

The White House told U.S. Immigration and Customs Enforcement that the plan was intended to alleviate a shortage of detention space but also served to send a message to Democrats. The attempt at political retribution raised alarm within ICE, with a top official responding that it was rife with budgetary and liability concerns, and noting that “there are PR risks as well.”

After the White House pressed again in February, ICE’s legal department rejected the idea as inappropriate and rebuffed the administration.