One gap between liberals and conservatives is their sense of the direction the country has recently taken. Each side perceives a nation that has abandoned valuable principles that were prevalent in the past. Sometimes, both sides’ perceptions are exaggerated. For instance, gross government spending has neither soared as a result of Obama and other recent spendthrift lefties, nor has it plummeted due to neoliberal budget-cutters. It looks fairly similar from decade to decade. (The upper trend includes entitlements and interest payments; the lower is limited to direct government spending.)

But there is an important way in which the progressives’ perception is valid. Ideas that are now embraced mainly by Occupy protesters and the Sanders campaign were once so mainstream that they provided the basic planks of the 1948 Democratic Party Platform. I quote from that document (italics added):

• We shall enact comprehensive housing legislation, including provisions for slum clearance and low-rent housing projects initiated by local agencies. This nation is shamed by the failure of the Republican 80th Congress to pass the vitally needed general housing legislation as recommended by the President. Adequate housing will end the need for rent control. Until then, it must be continued.
• We advocate such legislation as is desirable to establish a just body of rules to assure free and effective collective bargaining, to determine, in the public interest, the rights of employees and employers, to reduce to a minimum their conflict of interests, and to enable unions to keep their membership free from communistic influences.
• We favor the extension of the coverage of the Fair Labor Standards Act as recommended by President Truman, and the adoption of a minimum wage of at least 75 cents an hour [$7.42 in 2015 dollars] in place of the present obsolete and inadequate minimum of 40 cents an hour.
• We favor the extension of the Social Security program established under Democratic leadership, to provide additional protection against the hazards of old age, disability, disease or death. We believe that this program should include: Increases in old-age and survivors’ insurance benefits by at least 50 percent, and reduction of the eligibility age for women from 65 to 60 years; extension of old-age and survivors’ and unemployment insurance to all workers not now covered; insurance against loss of earnings on account of illness or disability; improved public assistance for the needy.
• We favor the enactment of a national health program far [sic] expanded medical research, medical education, and hospitals and clinics.
• We will continue our efforts to expand maternal care, improve the health of the nation’s children, and reduce juvenile delinquency.
• We approve the purposes of the Mental Health Act and we favor such appropriations as may be necessary to make it effective.
• We advocate federal aid for education administered by and under the control of the states. We vigorously support the authorization, which was so shockingly ignored by the Republican 80th Congress, for the appropriation of $300 million [almost $3 billion today] as a beginning of Federal aid to the states to assist them in meeting the present educational needs. We insist upon the right of every American child to obtain a good education.
• We pledge an intensive enforcement of the antitrust laws, with adequate appropriations. … We advocate the strengthening of existing antitrust laws by closing the gaps which experience has shown have been used to promote concentration of economic power.
• We support the right of free enterprise and the right of all persons to work together in co-operatives and other democratic associations for the purpose of carrying out any proper business operations free from any arbitrary and discriminatory restrictions.
• The Democratic Party commits itself to continuing its efforts to eradicate all racial, religious and economic discrimination. … We again state our belief that racial and religious minorities must have the right to live, the right to work, the right to vote, the full and equal protection of the laws, on a basis of equality with all citizens as guaranteed by the Constitution.
• We recommend to Congress the submission of a constitutional amendment on equal rights for women.

To be fair, the platform also diverges in some respects from contemporary progressive thinking. The environmental policies are mostly about supporting big projects that will extract more power and natural resources from public lands. That was Midcentury Modern progressivism, which lost its appeal in the 1960s. The platform is very positive about the Farm Bill, which may still receive Democratic Party support today but is unpopular among progressive activists. And the platform calls for tax cuts, albeit focused on lower-income Americans and as a response to post-War defense cuts.

Overall, the 1948 Platform seems left of the contemporary Democratic Party. It is, however, true that some important proposals of the 1948 platform were enacted by 1972, and today’s mainstream Democrats tend to want to protect those policies. In that sense, the mainstream Democratic Party is arguably the most conservative force in the country today (and I mean that respectfully). Its goal is to preserve what was constructed from 1932-1968. Meanwhile, Senator Sanders can be pretty accurately described as someone who wants to check the unchecked boxes on Harry Truman’s 1948 to-do list.

See also: Wyoming has moved right, the country has not moved left; Edmund Burke would vote Democratic; and the left has become Burkean.