This beauty was uttered by Speaker of the House Nancy Pelosi, referring to Trump’s reaction to her comments about him engaging in a cover-up. Here is the context:
“This is why I think the president was so steamed off this morning, because the fact is in plain sight, in the public domain, this president is obstructing justice and he’s engaged in a cover-up, and that could be an impeachable offense,” the San Francisco Democrat said at a progressive conference.
This is a nice congruent conflation of “pissed off” and “steamed (up)”, both meaning to be angry. My guess is that Speaker Pelosi was thinking “pissed” but quickly realized that would not be a prudent thing to say in public. Just guessing. I will note for the record that “steamed off” is a phrase, but it normally means to leave or depart in an angry or animated manner. A big tip of the hat to Mike Kovacs for hearing this one!