It begins with a gut feeling that you're right. That's unavoidable. It's an assertion that your beliefs, if not divinely-inspired by faith in one's Book, are most certainly beyond a rational critique. The righteousness of your desires means everyone you meet must be in favor of pursuing your ideals; or, at least, they are simply too weak or ignorant to be heard out.
The emotion you bathe in is called "Patriotism," involving the willingness to defend farm owners who knowingly violate federal law and are convicted of stealing money from the government which, may I remind you is, "of, by, and for the people." It's an endorsement of the freedom of a government to allow thievery in the name of "freedom," but to use "freedom" as an argument to permit the government from allowing men and men, or women and women, to get married equally under the law.
It starts with a frothy grin at ignoring your political enemy's scientific - literally, scientific - arguments for averting climate change, or at least punting on issues like evolution to avoid upsetting your political radicals. It transforms into repeated denunciations of your enemy as a liar, when in actuality you are ignoring your own numerous failures...
...Suddenly, you discover yourself offended that another state's congressman may refer to your constituents as "crazy." When called flatly out on your lack of following through with what you beg is the solution - bipartisanship - you stammer, mumbling that you are insulted and just won't stand for it!
Then there are videos of the other party popping up on the internet, wherein they are accused of calling you a coward! Of all the things to call you! You who surely have more virtue than the one you're deigning to debate with! You scream that you're being humiliated! It doesn't matter how many times your party claimed the President is a secret Muslim Communist, because at least you never challenged their bravery.
You're right, god damn it! You've gerrymandered the potency out of poor peoples' votes because they were too weak to see it coming! That, and by doing so you can create districts where you can't possibly lose an election! If you were wrong, somehow, surely their ideas would win on the "marketplace of ideas."
Only you could fail to address a broken system, one that disenfranchised the majority of Americans voting for President more than once due to an archaic "Electoral College," even in the face of a major scandal. You most definitely had a mandate to "do whatever was necessary" to protect the system which put you in power. The fact that a real threat to American lives had just scored a major blow to our morale was a sign that we needed to straighten up.
By shopping, of course! And by ignoring any war crimes that may have been committed. And by incarcerating the man-to-become-womanresponsible for leaking some of them! Just because people like her and Edward Snowden had to break the law to reveal illegal American actions doesn't mean we're wrong. It just means it's because this man wants to become a woman! Because they claim they are a woman! That's so against our values we can focus on that to stop ourselves from thinking about any unconstitutional punishments we've inflicted on her and their ilk! Shame on that guy for sharing a URL to classified material, right? What was his name, again?
"Enemy." That was his name. As you wake from your fugue state and realize that you were once a political party with significant dreams, you notice that you've gone too far. Sure, those fantasies about being the only country without a national health care system were nice, but trips to the ER really do drag down society. Giving people free homes would actually be cheaper than leaving them to get sick and go to the ER!
You recognize that defunding the government over political differences is not only a stupidly reckless idea, but is not even the right thing to do. It's not simply a matter of "not worth it," either - you are simply doing the wrong thing when you threaten to allow things like the Department of Homeland Security to shut down if you don't get your way on an immigration policy enforced in large part by...The Department of Homeland Security!
Finally, you realize that you aren't just wrong for being so partisan; you're wrong for not having realized it was wrong, in the first place.