It is customary in some Eastern traditions to cross oneself at each petition in a litany, and to closely associate oneself with a particular intention being prayed for or with a saint being named.
From the en.wikipedia.org
But of course, bringing up Marx in US political debate would get oneself nailed to a cross in short order.
From the guardian.co.uk
The idea is to bring oneself closer to Jesus Christ's suffering as he wore a crown of thorns and carried his cross.