Joshua Green takes a crack at imagining what Obama’s presidency would look like right now if there had been no filibuster in the U.S. Senate. It’s actually a very difficult thing to do. Let me explain why.

The most basic and obvious way to tackle this question is to look at the list of bills passed by the House of Representatives that did not pass in the Senate. Then you have to determine if those were bills the president would have signed. And did those bills have the support of at least 50 senators? Once you’ve identified all the bills that meet those criteria, you can present that as a package of stuff that would have become law if not for the filibuster. And, while that would be fairly accurate, it doesn’t really even begin to scratch the surface of how things would be different.

For example, I didn’t even mention judicial or political nominees. The filibuster has been used to slow down and block the confirmation of countless prospective judges and has left the executive branch far less than fully-staffed.

I think people can fairly easily understand that the filibuster is used to block contentious laws and prevent people with far-left views from finding employment in the public square. But what most people don’t understand is that the mere existence of the filibuster has a tremendous impact.

When the Democrats had control of Congress in 2009-2010, they still needed some Republican votes to overcome the filibuster. (The only exception was for a three month period between September 2009 and January 2010, when they did actually have the sixty votes they needed to pass ObamaCare through the Senate). Because the Democrats knew they had to attract some Republican support in the Senate, they passed bills in the House that were designed to win Republican support instead of what they would have done on their own in a parliamentary system. One example was the Cap & Trade bill that was based on Republican ideas and resembled McCain and Palin’s plan from their campaign.

As for healthcare, the role of the filibuster is more pernicious. Health care policy was discussed and built up in Washington think tanks during the 14 years between the failure of Clinton’s plan and the beginning of the 2008 presidential campaign. Obama, Edwards, and Clinton’s health care plans were all very similar because they all came out of the Washington consensus that had built up about what could conceivably pass into law rather than what would be the best way of creating a universal system. But the calculus of what could pass was done with the full knowledge that nothing would pass with less than 60 votes. In other words, just by existing, the filibuster took a single-payer system out of the conversation and out of the consciousness of the nations’s best health care thinkers. Anyone who continued to talk about single-payer, like Dennis Kuninich for example, were considered fundamentally unserious. And they were unserious. If they wanted single-payer, they needed to kill the filibuster first.

The truth is, if Washington hadn’t had to deal with the filibuster, the whole health care debate would have been different. Obama and Clinton and Edwards would have been calling for single-payer or would have lost to a candidate who was talking about it. The president would have been able to craft a plausible platform with progressive solutions and still be taken seriously. And he could have passed everything on his agenda in the first two years in office.

So, not only would the president have signed everything Nancy Pelosi produced in 2009-2010, but what Pelosi produced wouldn’t have had to be watered down to appeal to a few straying Republicans.

Finally, we have to talk about delay. The filibuster and other other procedural tactics have been used by Senate Minority Leader Mitch McConnell to simply chew up legislative days. They have filibustered bills they support just to make them take three days to pass instead of five minutes. By slowing down the process, the Republicans reduce what actually gets done.

In any case, it’s very hard to say what Obama’s presidency would be like if he hadn’t had to deal with the filibuster, but there are two things you can be certain about. First, he would have been able to be much more aggressive about fixing the economy and we’d have a clear record to evaluate. We wouldn’t be asking if the Republicans are trying to ruin the economy to hurt the president, because the Republicans wouldn’t have had the power to do things like that (at least, not in 2009-2010).

It’s also clear that progressives would be a lot happier with Obama in a world without the filibuster, but they should be careful what they wish for. Without the filibuster, a Republican congress would actually be able to do all kinds of things we don’t want like privatize Medicare and Social Security and outlaw abortion.

The filibuster works as ballast for the ship of state. It keeps our government very stable and predictable, regardless of which party is in charge. This has many benefits that people don’t consider because you don’t value what is not there. But, the problem now is that the ship needs to change course and the filibuster is preventing that from happening.