"How deep in Apple's pockets must these politicians be to be refusing this tax being forced onto their country and the benefits it could have for their constituents?"
Yet again we have to explain.
Apple locates in one country.
The country that they land in gets corporation tax of x% of How Much!!!.
x% of How Much!!! is a tidy sum.
What's more it's a tidy sum more than zilch which is what all the other countries get.
It's a competitive bidding situation. Ireland put in the lowest bid and got the gig. That benefits their constituents because it brings that tidy sum into the nation's coffers. It also brings some employment although not in proportion to the amount of money that's flowing through the company. For extras it also means that the corporation tax for all other Irish companies is lower as well and that puts those companies, including those that employ proportionate numbers of people, at a competitive advantage.
In short it's a big win for the constituents, so much so that ever since Ireland won the rest of the EU governments who missed out have hated Ireland for it. That's why things have ended up this way.