There are two ways to reduce those risks to zero: 1) The Town can pass a Resolution saying that it approves of such ordinances, and intends to pass them in the future. The ACLU cannot sue against a mere expression of opinion, which is what a Resolution is. Any ACLU suit against one will be thrown out of court, with fees and costs awarded AGAINST the ACLU.
2) The Town can pass the ordinances now, but with an effective date of "30 days after the final US Supreme Court decision concerning Hazleton, Pennsylvania, ordinances on illegal aliens." Again, the ACLU would be thrown out of court if they sued right away, because a law is not really a law and subject to suit until it has gone into effect.
Bottom line: your friends have these two ways to move ahead without fear of anything the "open borders" types at the ACLU, might do.
John / Billybob
With the ACLU it all comes down to collecting those court costs; that's how they pay salaries.
Cut off that pipeline and they will disappear.