Weird political move though, shrinking your power.
"If you elect me, I'll nullify the government's power!"
I mean, yes please, bring it on - but I can't see the incentives aligning for someone to actually do that.
Which makes me believe: any politician who promises anything along the lines of shrinking government power must be lying.
There are a few incentives to shrink the federal government that I can think of, both positive and negative.
I'll have to put more thought into it, though.
Negative:
1. Centralization of Political Power - Deflating the state may actually centralize political power. A heavy bureaucracy can make it more difficult to change the system due to all the rules and regulations. A slimmer, more efficient government could streamline processes and make it easier to change the status quo.
2. Political Pandering - As you said, a politician claiming they will shrink the government may simply be pandering for votes. They might shrink what they don't like while further funding what they support.
Positive:
1. Status and Power Dynamics - Power can be seen through different lenses. Being at the top of the hierarchy in a failing state may not hold much status. A politician may prefer to have less centralized power but hold a very high international status due to the proliferation of their state.
