In the long run we're all dead

This is generally good advice:

http://fakenous.net/?p=46

http://fakenous.net/?p=54

http://fakenous.net/?p=77

That said, I don't think the fundamental problem is lack of skill at the art of argumentation. Mind you, many people would benefit from a course in informal logic, standards of evidence, &c.

The main problem is that many people want certain results, want a particular outcome, and they don't care about the quality of the argumentation. They just want the results. The outcome is what's important, not the means. On that view, a persuasive bad argument is better than an unpersuasive good argument. It's not about true, reason, and evidence. Rather, argumentation in political discourse has a purely instrumental value, to further or secular the objective. The only value is the desired outcome. How you get there is secondary. 

Trained philosophers sometimes resort to atrocious arguments. It's not due to lack of skill. If they're sufficiently invested in an issue, a philosopher may reason just a badly as someone with no training in logic or probability theory. It's too idealistic to think this is just about honing one's skills in the art of argumentation.

If people think this life is all there is, then they are liable to be impatient about the finer points of argumentation. Time is running out to get things done. Lost opportunities can't be redeemed. There are no eschatological compensations. As John Maynard Keynes, put it, "In the long run we're all dead!" So it's now or never. 

If that's their perspective, then the priority is to achieve the goal by any means necessary, as expeditiously as possible. On that view, a convincing lie is more efficient than a complex argument. It comes down to the utility of political discourse to further the agenda.