This government shutdown is the least surprising thing to happen since Barack Obama took office. It's been inevitable for some time, and to be honest, I'm surprised that it didn't come sooner during one of fights over the debt ceiling. The unfortunate reality is that this is exactly what Republicans - or at least tea party Republicans - have wanted for a long time. Republicans believe that a) the government is too large and b) that the government spends too much money.
Therefore, "starving the beast", as it were, is the only way to create what they would consider substantive policy to limit the size, scope, and spending of the U.S. government. To use an Obama analogy, they want to use a chainsaw to cut the U.S. budget, when a scalpel is necessary.
Sure, the U.S. government spends too much money. Democrats, Republicans, liberals, conservatives, libertarians, etc. all agree with that. But just what the government SHOULD be spending the money on and what it shouldn't is not at all agreed. Conservatives typically believe that we should be cutting any and all social programs; including education, health care, medicare, medicaid, unemployment, etc. Basically those things that support the majority of older and low-income Americans - and don't create profit. While Democrats typically want to cut things like military spending, tax subsidies to wealthy individuals and companies, and raise corporate taxes. These are two different perspectives on the role of government, and to be fair are worthy of a legitimate, healthy debate.
However, the arena for hashing out this debate is not a continuing resolution to pay the government's bills. Especially when Republicans are using it as an excuse to defund the signature legislation of the Obama administration, before it's even been implemented. Republicans don't even want to give it an opportunity to work, even though the American public essentially supported the ACA by re-electing the man whose name has become synonymous with the law.
So by shutting down the government, Republicans have essentially won this round. We can only hope that the American people see what they are trying to do and recognize that Republicans are not attempting to defund Obamacare (the ACA), but instead trying to starve government to the point of ineffectiveness, so that only those essential functions will be taken care of (which for them is military only). There's a good chance Republicans will take the PR hit for this government shutdown, but Americans are so apathetic, misinformed, and myopic, that unfortunately I don't think this government shutdown will have an major electoral impact.