Their crime: signing a letter to Secretary of State John Kerry last month urging him to reject Keystone, which would carry oil sands from Canada to Gulf Coast refineries.

“Your member of Congress is trying to destroy job opportunities for our LIUNA brothers and sisters,” said the letter signed by Terry O’Sullivan, the general president of LIUNA.

“For every action, there is a reaction, and our reaction to this frontal assault on our way of life needs to be loud and clear. If you do not stand with us, we sure as hell will not stand with you,” O’Sullivan wrote, noting the jobs Keystone would create for union members.