Here is a sentence from a newspaper article:
The new foray [President Trump's statements about the voter fraud] into such a sensitive topic is not likely to go over well with Republicans in Congress, who are boarding buses and trains to disembark Washington for Philadelphia and their annual policy retreat — this time with a Republican president and vice president who are expected to attend.
I understand the general meaning of the sentence, that now, the recent words of President Trump have pretty good chances to materialize into some legal action. But I cannot understand the part about Republicans boarding buses, highlighted with bold.
The word disembark in my dictionary and in the reference provided by Google has only one meaning: to leave a ship, aircraft, or train (or other vehicle). So its use here confused me, because it looks like the Republicans are boarding buses in order to disembark in Washington and then move to Philadelphia for their annual policy retreat. But this is something like a nonsense (why can't they board trains directly to Philadelphia?).
The common sense is suggesting that they are moving from Washington to Philadelphia, but this does not coincide well with the dictionary meaning of the word "disembark".
So could anyone clarify this for me, please?