But until recently, the majority of the Board of Supervisors sided with immigrant-rights advocates, including the ACLU, Santa Clara County Public Defender's Office, agencies that help victims of domestic violence and the Justice for Immigrants steering committee of the Catholic Diocese of San Jose. They argue that the no-holds policy has improved public safety by increasing immigrants' trust in local law enforcement officials and reducing their fear of reporting crimes.

Now, three recent developments increase the chances that the board, which is scheduled to review the policy at a public meeting Tuesday, could very well back away from one of the nation's most lenient immigration policies.

COMPROMISE POLICY

Last month, left-leaning San Francisco formally adopted a slightly less immigrant-friendly policy than Santa Clara's, giving the county political cover to move to the right. And in an even more significant milestone, immigrants-rights advocates threw their support behind a landmark state law last month that allows counties to set their own detainment policies within certain broad parameters.

The law shields illegal immigrants who are arrested for minor crimes from being held for several extra days past their release dates for ICE agents. But under the so-called Trust Act, counties also can choose to detain those charged with or convicted of a long list of offenses, ranging from homicide to gang-related crimes to child abuse.

Another factor likely to affect the county's stance is that the board has two new members -- former state Sen. Joe Simitian, who represents Palo Alto and other affluent North County communities and is often a voice of moderation, and Cindy Chavez, a former San Jose councilwoman and labor leader.

They may join Supervisor Mike Wasserman, who opposed the current no-holds policy, in supporting at least one key change -- removing the county's current requirement for ICE reimbursement.

If so, the county would be left with the compromise policy that public safety and justice officials reached in 2011, which was approved but never implemented because of the last-minute addition of the reimbursement condition.

Under the policy, some jailed undocumented immigrants would be held for ICE for 24 hours, including anyone who has ever been convicted of homicide, as well as those who have committed a serious or violent crime within the past 10 years. No detainer requests would be honored for anyone under 18.

ICE also often asks counties to hold jailed legal immigrants who are not yet citizens and have been arrested for or convicted of certain crimes.

UNINTENDED CONSEQUENCES

Chavez, who may end up being the swing vote, said last week she hadn't made up her mind. She represents the same heavily Latino District 2 as the champion of the current policy, disgraced former Supervisor George Shirakawa Jr. He resigned in March after pleading guilty to 12 crimes, including misusing his county credit card for fun and meals, filing false campaign reports and stashing his donations in a secret gambling slush fund.

But Chavez also won a special election recently by trumpeting her record as a supporter of public safety.

Supervisor Dave Cortese, who is running for San Jose mayor, strongly supports the no-holds policy, which he says both reduces the county's jail costs and protects people from what he believes is unconstitutional detention. Supervisor Ken Yeager also voted for it in 2011.

Two liberal congresswomen who support national immigration reform, including a pathway to citizenship -- Zoe Lofgren, D-San Jose, and Anna Eshoo, D-Palo Alto -- recommended in a Sept. 3 letter to the board that the county adopt the Trust Act because "there is value in its uniform application across the state."

The current policy may be having unintended consequences, according to a report by the County Counsel's Office. Employees of the county's Pretrial Services department say there may be a link between a drop in the percentage of people who make it to all their court appearances -- from 87.6 percent in 2010-11 to 84.3 percent in 2012 -- and the no-holds policy. The department has received unconfirmed reports from its officers that ICE agents wait outside county courtrooms with laptops containing booking photos of undocumented defendants, taking them into custody when they appear for their proceedings.