According to Merrill Peterson via Snopes.com
It was easy to understand Lincoln’s appeal to social radicals, said [socialist William J.] Ghent, for he held very advanced views of the rights of labor. As early as 1847 he had written, “To secure to each labourer the whole product of his labour, or as nearly as possible, is a most worthy object of any good government,” which was remarkable for a prairie lawyer of that time. Speaking in New England in 1860, he praised the right to strike, as then being exercised by the shoemakers of Lynn. His clear assertion of the labor theory of value in the 1861 message — “Labor is prior to, and . . . superior to capital” — and his answers to the addresses of workingmen abroad and at home gave a color of Marxism to his thinking. He was, surely, the best friend labor ever had in the White House.