I suggest that both many progrssives and many conservatives are irrationa, and with the same variety of bad thought processes.
False pre-supposition, logical conclusion is by far the most common. You see this in wife beating questions the media asks of conservatives.
Guilt by association on top of bogus start. Richard Spencer has not denounced some obscure racist nobody ever heard of. Bannon did not censor Spencer. Trump hired Bannon. Therefore Trump is a racist. Guilt by association almost always has an early pre-supposition that is suspect.
Guilt by role. It is the duty of an attorney to represent his client and the best interests of his client. The left holds it against a Republican who was a lawyer for a businessman. The right holds it against a Democrat who was a lawyer for a street gang member.
Proof by anecdote. Too many anecdotes to recite.
Proof by statistics. Too many to recite.
Refusal to admit the sausage factory. Reagan had two priority goals and many lesser goals as president. In the Grand Compromise Reagan and Speaker Tip O’Neil made a deal. Tip would allow Reagan to cut taxes and defeat Communism. In turn Reagan would let the Democrats spend like drunken ... like Drunken Democrats.
So Reagan’s Supply Side Tax Cut greatly increased tax revenue. But the combination of increased defense spending and Drunken Democrat spending exceeded the increased tax revenue and Reagan had budget deficits.
The left conveniently ignores the increased spending and claims that Supply Side tax cuts don’t work because there was a deficit under Reagan.
Many Bush type Republicans don’t want to admit Voodoo tax cuts work. So they don’t want the truth of the Reagan era to be spread.
And those who do support Supply Side tax cuts don’t want the name of Reagan sullied by a Compromise ... let alone the Grand Compromise.
There are many other styles of irrational argument.
Can anyone make a factual, logical case for Repeal of the Law of Supply and Demand when it comes to Global Trade or Immigration? Nobody has made one yet.
From Smoot Hawley to Bush II sheet steel every single anecdote says attempts to repeal the law of supply and demand have failed.
Recent immigrants (legal and illegal), especially Hispanics, did not create the defects in our legal system. They did not create our welfare system. Yet they are blamed for our current situation that we older Americans created.
There is a big difference between immigrants who work and those who collect welfare and/or rape and steal. Yet some Populists illogically lump them all together.
Conclusion. None of us are perfect. Yes, The Left is illogical. But we should be careful before we embarrass ourselves with hypocrisy.
I hope my saying so does not result in anyone now hating you --- because they already hate me (and I applauded what you'd said, so it must have been wrong, etc.).