If it is necessary to intrigue both politicians and the public about a new transit system in order to get it funded, the necessary corollary must sometimes be choosing the wrong transportation mode from a technical perspective in order to satisfy political demands.
I think the most obvious example of this is the choice when upgrading a transit corridor that currently uses conventional buses. Often the most cost-effective choice is upgrading to Bus Rapid Transit, giving buses a dedicated right-of-way, higher speeds, and longer distance between stops. Essentially, a bus acts like a rail vehicle, but it's far cheaper to build the infrastructure for BRT than for a Light Rail or streetcar line. So why, then, are the Twin Cities looking at reviving their streetcars for the Nicollet and W 7th St transit corridors? Well, the easy answer is that the romance of streetcars will bring more public support than the boring and confusing option of BRT.
Freemark also has a critical post up on a proposed streetcar line in New York. The upshot is that if streetcars are the most politically viable option, then it's important to ensure that the streetcars are modern ones that can match or exceed the capacity and utility of BRT. Such vehicles are readily available and in use in many European cities.
As a side note, the two companies that make the rail vehicles most cities use are Bombardier and Siemens. It is unfortunate that America has to import our vehicles from companies based in Germany. But I see this as a direct consequence of our emphasis on automobile infrastructure over the last half-century while Europe built up their mass transit systems. There just wasn't demand for passenger rail vehicles in the US, so we lost those high-quality manufacturing jobs to German companies. I doubt they're coming back. So as we try to catch up on our transit infrastructure, we're doing a lot of stimulating the German economy instead of our own.