You must have a dog in this fight.
Most conservatives I think believe that some government functions are necessary and constitutional. For example, the military at the federal level, and police at the state and local level.
Therefore, we need some form of taxation. I would say conservatives want taxes to be fair, broadly based, and only as big as necessary to pay for necessary government functions.
In this case, I would be fine if a state decided to lower their sales taxes (Virginia sales tax is 5%, so it isn't too bad, but we also have an income tax, also not terribly high, and localities have property taxes, which pay for schools, police, fire, and other government services.
I believe that all of those taxes are OK at a limited level, and having multiple types of taxes is good because it levels out the effects of economic downturns.
In this fight, my concern is for the fairness aspect. For a tax to be fair, it should apply to every person who does the same thing, and it should apply at the same level. For example, everybody who buys a $20 copy of the Federalist Papers should pay the same sales tax.
And it is that way in every state I've checked, legally: either a store collects the sales tax, or the purchaser pays the sales tax either monthly, quarterly, or yearly (depending on what state you live in).
But practically speaking, few people follow the rules, and it costs the state too much to try to enforce the rules when people don't. So, you have three people -- one buys the book at a local store, one buys it from Barnes and Noble, and one from Amazon.
The first person pays sales tax, and the money paid for the book enriches the local economy.
The second person pays sales tax, because B&N has business in most states.
The third person pays no sales tax, because Amazon is located in very few states.
The 3rd person should pay the tax. People who believe in following the law will pay the tax, but people who break the law if they can get away with it don't pay the tax.
I don't like that. I obey the law, I pay the tax, but others don't. Just like I obey the law and don't loot stores, while other people do if they think they can get away with it.
I don't think that people who buy stuff locally, people who buy from the "wrong" online store, or people who believe their signature on their tax form is an oath, and therefore pay their "use tax", should bear the additional tax burden for people who ignore the law because they can "get away with it".
So I support limited federal action to make it possible for states to enforce their "use tax" laws -- thus convincing people to obey the law, if not because they are moral, then because they are afraid of getting caught.
I know some conservatives here at FR think states tax too much (I think most states do -- I don't feel particularly overtaxed here in Virginia, but I understand others do). But if you think taxes are too high, the answer is to rally the people, lobby the state government, and vote people in who lower the taxes. The answer is NOT to find ways to cheat on your taxes, and passing the burden of paying for government to others who won't cheat.
I'm certain each of the freepers who complain that their state already "gets enough money" and therefore think it's OK to cheat would not hesitate to call the police if their house is broken into, the fire department if their house is on fire, an ambulance if they have an emergency, or the state DOT if their roads haven't been plowed after a storm, or if there is a big pothole.
I would speak out equally against people trying to cheat on their income or property taxes. I don't think it is "conservative" (or "christian" for those who profess faith) to deliberately disobey the laws of the duly elected governments, when those laws are legal and constitutional.