In an address in North Carolina, FDR said:
In those days, 1913 and 1914, the leadership of the Nation was in the hands of a great President who was seeking to recover for our social system ground that had been lost under his conservative predecessor, and to restore something of the fighting liberal spirit which the Nation had gained under Theodore Roosevelt. It seemed one of our great national tragedies that just when Woodrow Wilson was beginning to accomplish definite improvements in the living standards of America, the World War not only interrupted his course, but laid the foundation for twelve years of retrogression.
Yes, you read that paragraph correctly. Now does FDR actually believe Teddy was a "liberal"? No probably not. But FDR was retcon-drunk trying to retroactively change progressivism's back story after the deathblow 1920 election. And in changing history as FDR was doing, it simply required calling Teddy Roosevelt a liberal too on account of consistency. FDR also did this to Wilson, BTW.
Now, the thing is, I do not believe Theodore Roosevelt was a "liberal". And neither do you.
But this is a litmus test. If you are the kind of person who is willing to agree that progressivism = liberalism then you don't get to exempt yourself, you have to be consistent. You need to call Theodore Roosevelt a liberal as well because Teddy was a big time progressive, a big time statist and he was not a fan of the kinds of things related to governmental limitations. Theodore Roosevelt wanted maximal government.
Like all other progressives, Theodore Roosevelt was a postliberal. He wanted to get past the Constitution. Get past government limitations. Get past John Locke. Get past anything and everything related to the idea that he, Teddy, could not do whatever the heck he wanted to do. There is a whole party platform from the 1912 Progressive Party, Teddy's Party, explaining what exactly they wanted the government to be able to do to us.
Note how the 1912 Progressive Party is not the Liberal Party.
Progressivism was the first postliberal ideology to be seen in the U.S. Good job on you for being consistent in your refusal to call Theodore Roosevelt a "liberal". Progressives are not liberals.