Back to the subject of the thread: Third party advocates seem to focus almost exclusively on miraculously winning the Presidency if "just enough" people vote third party, either suddenly or after a gradual increase of credibility with each election. The results of Ross Perot's 1992 effort demonstrated that both scenarios are incredibly difficult to pull off: He was a billionaire with a mainstream ideology telling Americans exactly what they wanted to hear at a less politically polarized time, and he still didn't produce a miracle. Moreover, instead of third party credibility growing from year to year after that, it quickly tapered off again (and laws have since been instituted making it even more difficult to break in). On top of that, third parties are deeply fragmented, which further destroys their effectiveness; you can't even get the Libertarian Party and Constitution Party to cooperate unless Ron Paul is running for the Republican ticket. Even after recognizing the platform that would bring them together, they STILL don't have the sense or modesty to merge under it.
However, those arguments sidestep the larger issue: Even if Perot had won in 1992, and even if he were actually Ron Paul wearing a mask, winning the Presidency is only enough to buy time. It is not enough for lasting political change, because for that, we need Congress as well. To take Congress, we need an enormous national infrastructure for simultaneously funding hundreds of races at once.
Simply destabilizing the two-party system with a third party Presidential win is not enough to achieve this:
After a sudden breakthrough, there would only be a small window of a "chaotic" political system where third parties had a chance, so it's unlikely that any would surpass either the Republican or Democratic Party in enough elections to become the new party of a two-party system...and make no mistake, the two-party system would reestablish itself within two election cycles or so, because that's how our "first-past-the-post" winner-take-all plurality voting system works. The reason it would be so difficult for one of the third parties to supplant either major party is because they'd all be scrambling and fighting each other for the same piece of pie during their brief window of opportunity...even similar ones like the LP and CP. If we created a new third party, that would simply be another to add to the mix, because the others have already proven they aren't willing to merge or go anywhere. The third party route is the road to completely splintering the liberty vote, as proven by the Barr/Baldwin/Write-in-Paul/Abstain campaigns in 2008 and the Johnson/Goode/Write-in-Paul/Abstain campaigns in 2012.
With plurality voting, splitting the vote doesn't exactly do much for us...and as much as that applies to Presidential races, it applies doubly to Congressional races: During the brief window of "third party opportunity" following a miraculous Presidential win, a
single third party starting from an extremely limited funding base and infrastructure of nearly zero would need to win a huge number of Congressional seats immediately to even build the credibility to build the donor infrastructure for further wins in the future. (Otherwise, the system will settle again on the R's and D's.) This is a chicken-and-egg problem, because you can't win that many Congressional seats if you don't already have the donor infrastructure.
Under the current voting system, you need a huge preexisting donor infrastructure and mindshare to win a lot of simultaneous elections, and you need to have a proven track record of winning a lot of simultaneous elections to build up a huge donor system in the first place. This completely rules out third parties as a viable choice for taking Congress: The only way third parties will ever have a hope of taking power is if we change the voting system entirely...but we need to take power first to do that, so a third party-focused strategy is completely futile. Voting for third parties in general elections is still a great idea when there are no major party liberty candidates in the race, because after all, why not? Still, that doesn't mean it's a good idea to pursue third parties as our primary political strategy: Just because buying a lottery ticket for $1 gives you a chance to win does not mean it's a good idea to spent all your money on lottery tickets. There's a huge opportunity cost.
The strategy to take over the Republican Party has already shown gains in a very short amount of time with a very small number of backers, considering we've already taken over some state parties with activists alone. The rest of the state parties can be taken over the same way, and the RNC can be taken over the same way. The ONLY obstacle here great enough to cause failure is people's emotional unwillingness to have anything to do with the Republican Party...oh, they're too corrupt, too tainted, too dirty, blah blah, and we'll get the taint on us and end up just like them. (The latter is untrue, because unlike every other political movement ever, each of us have firm principles we're unwilling to compromise; we each differ on exactly what they are, but we present a stark contrast to every other political movement in the history of mankind, which has been based entirely on subjective utilitarianism in the pursuit of some abstract goal or religion.) If enough of us let that deter us, the strategy will fail...but at least there's a scenario where it can be successful, unlike the third party strategy.
Are there ifs, ands, and buts? Sure. Even after we take over, we'll have to fight the MSM's attempts to delegitimize the party and establishment attempts to create a new party to replace us...but even that will be a relative win over the current situation, because it has a better chance of giving other third parties an opening than any other strategy. If we instead pursue a third party political strategy from the outset, we'll get as far as the LP has gotten and continues to get...unless we split the third party vote up farther by creating a new party, in which case the additional fragmentation will cause us to come up even shorter. (Now, if the entire country collapses before we can stop it, THEN the party system could really be shaken up, but nobody can accurately predict what will happen at that point.)
Now, pursuing political action is the only way to actually change laws and policies: Agorism won't bring down the state, because an economy without famine is an economy that relies on large-scale capital goods to produce consumer goods, and those can't exactly be hidden from the IRS. The state will always be able to tax enough to exist and enact violence, so it cannot be ignored. However, there are a LOT of other things that need to be done aside from - that is in addition to, not instead of - political action:
We need to become influential voices in our communities and beyond. We need liberty teachers, professors, economists, journalists, talking heads, authors, artists, comics, TV/film directors/producers/writers, lawyers, and pastors. We need people to take on influential roles in their communities...but that said, a lot of community roles come back to government and politics: Sheriffs, county commissioners, prosecutors, school board members, etc...we can avoid these positions to avoid becoming corrupted by them, but that guarantees they'll be filled by total statists. Weighing exposure and influence and denying positions to statists over hazards of the job are difficult judgment calls to make on an individual basis. (Is none of that your calling? Become an entrepreneur and try to make it big, so you have the funds to spread influence that way.

) These are the ways we will convert the masses to a libertarian or Constitutionalist or anti-federalist ideology: Not through logical argumentation, but by demonstrating influence, popularity, and ubiquity.