A Democratic aide confirms to me that Merkley will campaign on strengthening Social Security in a way that includes the push to make benefits more generous, not less.
“Strengthening social security and putting a few extra bucks in seniors’ politics (just going to assume that should be pockets -ed) is good politics,” the aide tells me. “Democrats shouldn’t run away from their strength on Social Security. In fact, they should put it close and center. Social Security is a successful government program that’s been central to the Democratic Party’s identity for decades.”
As the proprietor of this here website often says, people might even like expanded Social Security benefits. Including voters!
NOTE: Social Security expansion is also endorsed in the Progressive Caucus budget, so that's 70 more House Democrats on board.