I suppose that Parker might just be a protest vote against Roosevelt. I don't approve of his trustbusting and corporatist policies that distort the free market.
Not to be rude, but this analysis doesn't really hold up. For one thing, Roosevelt was far from the most aggressive trust-buster of the Progressive Era. William Howard Taft was much more heavy-handed when it came to making war on the big monopolies than TR was - in fact, that was one of the reasons for the Bull Moose campaign of 1912 - yet your post has you supporting Taft twice. You seem to be reacting to the pop culture image of these men more than their actual records, and the two differ quite a bit. I'm not sure what you mean by Roosevelt's "corporatist" policies - is this a reference to his support for labor unions?
On a more ideological note, I don't see how the monopolistic practices of the Trusts did anything but distort the free market. You don't have to be a socialist to acknowledge that monopolies - especially monopolies that abuse their power to send prices sky high - are a bad thing for the economy. Trusts like Standard Oil and others of its kind were a drain on American Capitalism, disrupting the natural cycle of the markets and using dishonest (and often outright illegal) practices to strangle the competition. This was an era in which striking workers were regularly gunned down by private detectives hired by company executives and profits were prioritized above workplace safety. One can debate the extent to which government intervention was appropriate, but the fact remains that something had to be done and the president was the only third party with the influence to do it.