Progressive Politics

Leftism is the pursuit of social equality and egalitarianism.

Democrats are social liberals.

Social liberalism: Social liberal parties stress civil and human rights and favour a social market economy.

Refer to social market reforms & social programs from the New Deal (social security, security & exchange commission, labor relations, wealth redistribution, consumer protections, fair employment practices, public housing, minimum wage), their continuation & expansion of civil rights from Great Society (civil rights acts, voting rights act, war on poverty antipoverty programs, medicare, medicaid, welfare, social security expansion, education programs), more recent market regulations, health care expansions, consumer protections (eg, Dodd–Frank Wall Street Reform and Consumer Protection Act, Affordable Care Act). This is a clear record of reforms to address social & economic inequality, improve education & healthcare, promote civil rights, regulate markets.

In terms of political spectrum

Generally, the left wing is characterized by an emphasis on "ideas such as freedom, equality, fraternity, rights, progress, reform and internationalism" while the right wing is characterized by an emphasis on "notions such as authority, hierarchy, order, duty, tradition, reaction and nationalism".

Political scientists and other analysts usually regard the left as including anarchists, communists, socialists, democratic socialists, social democrats, left-libertarians, progressives, and social liberals.

The Democratic party is made up of factions with the center-left & left caucuses dominating: it tends left.

Claiming Democrats aren't left (if impure) requires a level of delusion that outright denies basic definitions of left & political classifications, historical record, and usual knowledge of political scientists & analysts.