There is a lot of talk about "the center" and "centrists." Lots of people say the progressive blogs are on "the left."
To put this in perspective, when and where is the last time you heard anyone talk about nationalizing the oil companies? That would be a "leftist" proposal.
After all, the oil companies do not "own" the oil any more than anyone can own the air or the water. They are extracting OUR resource, under license from US to operate, and as corporations are granted limited liability by US. In exchange, they are supposed to be serving the public interest. A discussion about whether they are serving the public interest might involve questions about how much they are setting aside to cover the costs of putting carbon into the air, or to pay for research into transitioning away from fossil fuels a they start to run out, how much they pay their employees, and other ways that WE might benefit from allowing them to extract OUR resource. So obviously, they are not serving the public interest.
A broader discussion would ask whether we need to reform the corporate system into something that really does serve the public interest.
The fact is, "leftist" arguments are not even part of our national discussion. Without that perspective in the discussion, it can't really be said that there even is a "center," can there? And without ALL sides contributing to the marketplace of ideas, how can society arrive at solutions that incorporate the best ideas from all the different perspectives?