Hi Ned,
While I certainly can't speak for
@MikeyB a reasonable definition would be simply anointing a politician who has no military experience in exchange for their political support and or their ability to recruit men in their respective political districts.
Where it gets a bit more complicated is in the case of someone like Samuel Curtis who is an elected congressmen but did graduate West Point and did command two regiments in the Mexican-American War.
One could argue can that Curtis regardless of his occupation would be qualified to at least be a Colonel in the ACW some there was a severe shortage of graduates of recognized military academies.
Leftyhunter