Teddy Roosevelt himself was a progressive. As President he advocated for an Income Tax Amendment. The National Monetary Commission study that led to the Fed began during his administration. His great fame was as a trust buster. People oddly think that Wilson was the first progressive President.
Teddy was so much of a progressive that in the 1912 Election he ran for President on the Progressive Party ticket, the real name of the Bull Moose Party.
Which is part of the reason that I wanted McKinley to live. Roosevelt was a progressive who saw government as the answer to everything. Taft was a more limited government kind of guy. Roosevelt didn't do too much damage, though. He created the national parks and got us the Philippines. WIthout Roosevelt, and splitting the ticket in 1912, we would not have had Wilson and all the bad things he established. Politics in the 1912-28 period was a lot like now. You had progressive Republicans and you had Republicans who we would call conservative in today's terms. When Republicans got the White House back, and especially under Coolidge, Cal had a tough time getting taxes lowered and dealing with foreign countries because the progressive wing of his party would side with the democrats. Just like today.