“To pursue our progressive agenda, people have to have trust in our government.”
Basically the idea is that if progressives aka liberals want voters to vote for their big government agenda, liberals need to make sure that government works well by addressing corruption and inefficiency as major issues. It is rather unusual to hear a liberal speak to this. Generally government corruption and/or inefficiency is a libertarian or conservative theme. But it does make logical sense. If government corruption and inefficiency is reduced, voters will have less incentive to vote for a antigovernment agenda. (Of course there are still other reasons for them to vote against big government such as government intrusiveness/privacy concerns, tax rate concerns etc. But still it does reduce the impact 2 of the major items on the why not to vote for bigger government list.)
It will be interesting to see if any real candidates pick up the idea. I haven't seen it as a major liberal theme. Generally the liberal theme is government is good and is here to help you. I haven't previously seen any liberals saying - we will FIX government so that you the voter will believe it is good.