Oh hey, we've played this game before. And it went as poorly as informed people expected. More than once, if you can believe it.
I believe, based on absolutely nothing, that if mass deportations happen, then there'll be a change in the farming labor force. No one will do the work at current wages and the owners will resist raising wages. The vacuum will be filled by prison slaves because they don't get a choice and they get paid pennies per hour.
I don't know what the restrictions are on using enslaved prisoners, but if there are any, they'll be removed and the process to acquire them streamlined. That alongside enacting draconian laws to imprison and enslave even more people should be enough to offset the loss of migrant labor. I hope I'm wrong.