Firearms are my passion and hobby. I recognize that the RKBA is a fringe issue because the vast majority of voters are just not interested in firearms. If I could find politicians who were consistently for less government in all areas except firearms, I would vote for such politicians. But I have not found politicians who are consistently for less government, so firearms issues usually drive my vote.
Firearms happen to be a hot-button issue, because abuses of that right happen to be more visible, and usually more deadly. Other rights which get suppressed, are usually much more quiet and reside under the radar (or outright ignorance) of the so-called media.
In 1992, Bill Clinton managed to get Congress to pass a tax hike, which was retroactively applied to January 1, 2003. Not one newspaper took him to task, nor did one lawsuit get filed over the apparent violation of Article 1, Section 9 (ex post facto clause).
As you so astutely mentioned, both parties are merely carving up the middle, with a few fringe arguments giving the appearance that there are substantial differences between the two.
This past spring, I was so upset with the apparent selection of John McCain as the Republican candidate, I wrote to the RNC, advising them that I could no longer support them or their candidate apparent. The only thing I received in return was a form letter asking me to make another donation.
With the loss of this past Presidential election, and further erosion of power in Congress, Republicans choose a liberal RNC Chairman from Maryland! It proves your point succinctly.
This morning, Fox News mentioned that an increasing number of Republicans were referring to themselves as more conservative than Republican. One can only hope that this is a harbinger.