It could be because his vehicle-leasing company gets quite a bit of business from public entities, whose union employees might be pointed his way by word of mouth or other seemingly innocuous methods. Trickle-down referrals, so to speak.
In down times such as in 2009, as he noted, those public entities always manage to have budgets to spend, such as payroll, and civil "servants" willing to spend them.
No doubt many consider his an invaluable liberal voice worth heeding, as that narrow defeat in the 2016 Oregon District 4 Democratic primary to Peter DeFazio -- nipped by a mere 92 to 8 percent -- clearly illustrates.
Besides, everyone knows a car salesman's word is above reproach. Just ask his affluent friends.