There's another guard against it, which is the ability for congressional representatives to negotiate deals. They are not obligated to do whatever 50.01% of the

There's another guard against it, which is the ability for congressional representatives to negotiate deals. They are not obligated to do whatever 50.01% of the population prefers on an issue by issue basis, but rather to do what they think will win elections. Issues that people care about more are more important for winning elections, so politicians can compromise on broadly-supported issues people care little about in order to work on niche issues with intense support. In practice, this looks like things like pork-barrel infrastructure spending and farm subsidies. These sorts of things are pretty unpopular with most people, but they keep getting passed, and the above is why.