With all of the renewed fuss the Discovery Institute is trying to stir up over the Gonzalez tenure thing, this seems like a really good time to talk about the role of money in the tenure process. I'm not going to do this because the money issue is one that the Discovery folks are frantically trying to distract attention from (they are) or because Gonzalez's inability to land external funds means that he'd be a very weak candidate for tenure even if he wasn't involved in ID (it does). I'm going to look at the role of money in the process because it's hugely important, for more reasons than people unfamiliar with the inner workings of science realize.
The best place to start is probably with a rough description of what's expected from tenure-track faculty at a research university. Undergraduate teaching, which is probably the first thing that jumps to mind for most people when they hear "professor" is a relatively small part of that. A professor at a research university is expected to direct a research program - and there's a lot more to that than just doing research on your own. A good research program consists of a number of people working on either different aspects of a single question or on a group of related research questions. The professor who serves as the primary investigator running the program shapes the research, but doesn't work alone. Sometimes, there will be other faculty members who collaborate on some aspects. Sometimes, there will be postdocs who work on the project. There will almost always be students who are involved at different levels. There are as many ways to set up a research program as there are scientists with research programs, but they all have one thing in common: they involve more than one person. And that's where the money gets important.
To see why, let's look at all the things that a professor can't do without money:
With no money, you will be able to collect very little - to no - new data. You won't be able to buy the supplies you need to acquire new data on your own. You might still be able to do some research on your own, but you'll be restricted to either working with data that you collected when you had money or working with data collected by other people for their own experiments. Both of these methods have major limitations - the biggest being the inability to custom-design a data collection process to match your needs. Instead, you wind up modifying your goals to fit your limitations. The amount of money needed for data collection varies greatly from science to science, but it's never free. Even in a science like astronomy, there are expenses that go well beyond the cost of the gas to get you to the telescope. (For starters, the people who own the scopes typically expect the individual researchers to pick up their fair share of the operating expenses.)
With no money, you will have problems developing new collaborations with other scientists. You might be able to bring insight, experience, and expertise to a project, but your ability to make more tangible contributions to their research is limited. If you do form new collaborations, it will most likely be as a contributor to their research program, and not part of something that you're doing on your own.
With no money, you will not be able to hire postdocs. That's a problem for a couple of reasons. Having junior scientists working for you can go a long way toward making your lab more productive. It's also part of your job as a research scientist to mentor junior researchers. Postdocs, however, need something to eat and a place to sleep, and you can provide neither if you have no money.
With no money, you will not be able to support your graduate students. Graduate students are admitted by the university and the department, but in general each grad student is a member of one scientist's lab. That scientist is their advisor, and is the person primarily responsible for overseeing their education. In the sciences, graduate students are normally paid - either by the department as teaching assistants or through one of your research grants as research assistants. If you have no grants, then you effectively make the department responsible for the care and feeding of all of your students. This is not fair to the department, and it is not fair to the students - teaching assistantships don't contribute as much toward the student's education as a research assistantship does.
With no money, it is not likely that you will be able to do your job as a faculty member at a research university well.
I can already hear an argument coming: "if money is so important, how come Gonzalez's school didn't list it as an explicit requirement?" I didn't write their requirements, so I don't know the answer to that question for sure, but I suspect that it comes down to this - they didn't see a need to list it separately. Saying "we're going to look at your funding" is redundant. They are already going to be looking at how well you've done at establishing a new productive research program, and they can't do that without looking at the funding. Telling a research scientist that you are going to examine how well they've set up their lab and that you'll also look at their funding is like telling an artist that you're going to look at how well they can paint and that you'll also look at how well they hold a paintbrush.
I'm not saying that the current focus on funding is good. I'm sure that the current funding system is not. But when it comes to the way things are right now, the reality is that a research professor cannot do a good job if he or she cannot bring in outside money. As long as that is the case, money is going to be an overwhelmingly important factor when it comes to getting tenure, because it is an overwhelmingly important factor in how well the professor is doing the job. If a professor has brought in very, very little grant money, he or she will have very, very little chance of getting tenure at pretty much any research university.
In the case of Gonzalez, the average professor who was approved for tenure in his department had brought in $1.3 million. Gonzalez brought in $22,661 - which is less money than it takes to fully fund one grad student for one year in most places. With that kind of funding performance, Isaac Newton would have a hard time getting tenured.