Harry Truman wrote one reasonably long statement on illegal immigration. He wrote it in the context of signing, with explicit reservations, S. 984 on June 13, 1951 [to authorize guest farmworkers; this was during worst of the fighting of the Korean War.] The contents are interesting. It is quite clear that Truman opposed illegal immigration and supported deporting illegal aliens, both on principle and to stop new illegals from entering. A few quotes
"During and since the last war, the recurrent shortages of farm labor in the United States have made the addition of contract workers from Mexico a vital factor in bringing in the crops. Last year, for example, 70,000 Mexican workers were legally admitted to this country for contract work during the harvesting season."
The bolding is mine. We have an estimated 11 million illegals. Then as now, the actual need for migrant labor in agriculture is tiny compared to the number of illegals.
"But this is very limited progress, which hardly touches our basic farm labor problems. The really crucial point, which this Act scarcely faces, is the steady stream of illegal immigrants from Mexico, the so-called "wetbacks", who cross the Rio Grande or the western stretches of our long border, in search of employment. These people are coming into our country in phenomenal numbers--and at an increasing rate. Last year 500,000 illegal immigrants were apprehended and returned to Mexico. In 1949, less than 300,000 were returned."
"And many of them are exploited, I regret to say, and are left in abject poverty. They live always under the threat of exposure and deportation. They are unable, therefore, to protest or to protect themselves."
"The presence of these illegal workers has a seriously depressing effect on wages and working conditions in farm areas throughout the southwest. The standards of living and job opportunities of American farm workers are under constant downward pressure. Thousands of our own citizens, particularly those of Latin descent, are displaced from employment or forced to work under substandard conditions because of the competition of these illegal immigrants."
Truman held to quaint notions of supply and demand.
"Shall we continue indefinitely to have low work standards and conditions of employment in agriculture thus depending on the underprivileged and the unfortunate at home and abroad to supply and replenish our seasonal and migratory work force? Or shall we do in agriculture what we already have done in other sectors of our economy-create honest-to-goodness jobs which will offer a decent living so that domestic workers, without being forced by dire necessity, will be willing to stay in agriculture and become a dependable labor supply? Just as farm employers want able and willing workers when needed, so do workers want reliable jobs which yield a fair living. Neither is being satisfied."
Truman believed that the problem could be solved by paying American workers higher wages.
"It is absolutely impossible, without the expenditure of very large amounts of manpower and money, to seal off our long land borders to all illegal immigration. But these three actions by the Congress will give us the tools we need to find and deport illegal immigrants once here and to discourage those of our own citizens who are aiding and abetting their movement into the country."
"If we are to begin to meet the basic problem, we must do two things right away. First, we must put a stop to the employment of illegal immigrants.
First, legislation should be enacted providing punishment for the offense of harboring or concealing aliens who have entered this country illegally.
Second, legislation should be enacted to clearly establish the authority of personnel of the Immigration and Naturalization Service to inspect places of employment, without a warrant, where they have reason to believe that illegal immigrants are working or quartered. Immigration inspectors are able to cope with known illegal immigrants by obtaining warrants for their arrest.
Third, a supplemental appropriation should be made available immediately to the Immigration and Naturalization Service to expand its personnel in the southwest so that all types of enforcement work can be stepped up--including apprehension, investigation, and deportation of illegal entrants."
"It is absolutely impossible, without the expenditure of very large amounts of manpower and money, to seal off our long land borders to all illegal immigration. But these three actions by the Congress will give us the tools we need to find and deport illegal immigrants once here and to discourage those of our own citizens who are aiding and abetting their movement into the country.
After the Korean War emergency, a series of good government reforms following the principles outlined by Truman reduced the number of Mexican nationals in America doing farm labor -- such as Eisenhower deporting a huge number and the end of the bracero program in 1964 under LBJ following Edward R. Murrow's "Harvest of Shame" documentary. This reduced supply of labor allowed the fiercely anti-immigration labor union leader Cesar Chavez (see my 2006 article "Cesar Chavez, Minuteman") to win higher wages for farmworkers beginning in 1965, gains that were washed away by the flood of illegal aliens from the early 1980s onward.
Of course, all that history has been shoved down the memory hole, with Chavez having been recast as the patron saint of the Reconquista. In the modern liberal mind, race is vastly more important than class, so all these liberal heroes' actual views are inconceivable.