David Hogg is targeting incumbent Democrats because he views many of them as ineffective, out-of-touch, and asleep at the wheel. He aims to elect younger, more progressive leaders who will take a more aggressive stance, particularly against President Trump, as part of his effort to revitalize the Democratic Party and improve its electoral prospects.

David Hogg has faced criticism from party members, including James Carville and DNC chairman Ken Martin, who argue that targeting incumbent Democrats undermines party unity and the traditional goal of supporting incumbents to maintain power. Some centrists worry that Hogg's far-left approach could damage the party's brand, especially in swing districts.

David Hogg has acknowledged that many Democrats will be upset by his campaign, but he insists the party is in a crisis and that change is necessary. He has defended his initiative by stating that stories aiming to destroy his reputation will include lies and distortions, driven by those wanting to maintain the status quo despite its failures.

The group 'Leaders We Deserve,' led by David Hogg, focuses on intervening in Democratic primaries, particularly in safe Democratic districts, to support younger and more progressive candidates who challenge incumbent Democrats perceived as ineffective.

Yes, one notable supporter of David Hogg's efforts to intervene in primaries is Randi Weingarten, president of the American Federation of Teachers, who has significant political influence and ties with Democratic officials.