"go back to your country"
These united States of America contain more than 50 states (the territories, possessions, and tribes are all Free, Sovereign, and Independent States. It is just that only 50 of them have been admitted into the union of these united States of America.
There is nothing racist about the statement of "go back to your country".
Each of the four come from different countries within these united States of America. Going home would simply mean -- get out of DC and go back to your home State. At worst, unless the speak of those words declares that they meant something different; It seams that the person who spoke those words were telling those others that he thought they were not qualified for their job and should just go home.
#PresidentDonaldJTrump the person who supposedly spoke those words, also is unqualified for his job.
A news item states -- al be it incorrectly -- that:
"In the early days of America's Congress, it was considered forbidden to so much as discuss (let alone introduce) motions abolishing slavery since it was constitutionally protected. So it's all a bit complex."
Those words come from several unqualified people in the news. The latter one, who wrote or re-wrote the words I just quoted is #NicholasClairmont
Proof of incompetence:
Within The Articles of Confederation, our nation's first Constitution, it makes absolutely no reference to slavery, especially prohibiting laws to extinguish the use of them.
The unanimous Declaration of the united States of America certainly does not prohibit government from criminalizing slavery. In fact, the Declaration prohibits the people from owing slaves, with the statement that "all men are created equal"; though not always treated equally by others.
When we get to The Constitution for the United States of America, we find an interesting grant of power to Congress, regarding some element of slavery and the importation of people: Article 1, Section 9, Clause 1:
"The Migration or Importation of such Persons as any of the States now existing shall
think proper to admit, shall not be prohibited by the Congress prior to the Year one
thousand eight hundred and eight, but a tax or duty may be imposed on such Importation, not exceeding ten dollars for each Person."
The initial tax of $10 was the start of making it more difficult to get slaves.
The 1806 date, gave people 30 years to start phasing out slavery. At that 30-year mark, Congress was at full liberty to impose impossible taxes and duties on the importation of people. They also could pass laws to outright ban slavery.
But they did not.
Not working within the Constitution is nothing new then or now.
In 1860's; The Confederate States of America, in their constitution, included this phrase about slavery:
"The importation of negroes of the African race from any foreign country other than the slaveholding States or Territories of the United States of America, is hereby forbidden; and Congress is required to pass such laws as shall effectually prevent the same"
If the united States had no slaves at that time; how many slaves did the Confederate States of America really expect to get?
They were finding it less costly to mechanize; much the same as today. An act that increases the rate of unemployment. Did not have to worry about machines running away and need far fewer people to watch and care for the machines.
Just my 2-cents