Thats the problem, not that the Republicans are within their rights, but that they don't have enough political power to make the Democrats negotiate. Why should the Democrats sit down and negotiate if they don't have to? Except they do have the political power, clearly they do, because they are able to shut down the government and perhaps force a default if they don't get what they want. It doesn't matter that they don't have the political power to push through their own legislation, because neither do the Democrats. Technically we could say the same things about the Dems: Why do they want to dictate legislation when they don't even control both houses of the legislature?Point is, they've tried and failed to get what they want enough times before that their opinion is in the minority, or at least can be politically overruled in most circumstances. They may have enough power to be an annoyance but if they had enough power to make a change they would have already.
Its not a question of IF they have political power, its a question of if they have ENOUGH political power to bring about negotiation. The reason I posted the article is because even on first day of the shutdown, the Republicans already have dissent from within the party (the moderate portion of the party). A problem with inter-party dissent does not speak well to the ability of the party as a whole to stand firm on this issue. Do you think they have enough power to get what they want? I don't see the Democrats caving easily, and from what I can tell most people are blaming the Republicans for the shutdown (which doesn't help there negotiating position).