Webster's definition: The attribution of one's own ideas, feelings, or attitudes to other people or to objects; especially: the externalization of blame, guilt, or responsibility as a defense against anxiety.
In the political arena, it's the practice of attributing to one's opponent one's own asocial behavior.
Examples of projection:
1. "Voter fraud" (in practice: disenfranchising one's opponents)
2. "She lies" (in practice: fact-free debating)
3. "Tax & spend" (in practice: tax breaks for the rich & unnecessary military spending)
4. "Extramarital adventures" (in practice: taking advantage of women, weak laws, minorities, etc.)
5. "Liberal Media" (in practice: suppression of factual reporting)
6. "Unfair political advertising" (in practice: quoting one's opponent's own words)
7. "Global warming is a hoax" (in practice: it's an opportunity to externalize one's own environmental costs)
8. "Amnesty for illegal immigrants" (in practice: suppress the pay of domestic servants and farm laborers)
9. "Second Amendment Rights" (in practice: cede governmental control of commerce in firearms to the Gun Lobby)
10. "Citizens United" (in practice: gerrymandered Congressional districts and Political Action Committees)
11. "Politics as Usual" (in practice: low voter turnout in off-year elections)
12. "Right to Life" (in practice: reduced access to education and women's health care)
13. "Fox News" (in practice: creation of political information out of thin air)
14. "Campaign Platform" (in practice: a list of hot button issues)
15. "Social Security is a Ponzi Scheme" (in practice: privatization of the Social Security Trust Fund)
16. "In God We Trust" (in practice: exclusionary or suppressive religious tests and imposition of one's religious beliefs on others)
17. "Obama is a weak President" (in practice: quoting Sen. McConnell, "Our top priority is to make Obama a one-term President"
18. "Obama can't speak without a TelePrompter" (in practice: Trump on the Stump)
19. "The voters don't trust Hillary" (in practice: conservative fear of the female majority in America)
20. "One Man One Vote" (in practice: rich white men only)
21. "Right to Work" (in practice: suppression of labor organizations and reduction of workers' rights)
22. "Single payer healthcare" (in practice: Medicare for all)
23. "States' Rights" (in practice: Abraham Lincoln was a Republican)
24. "Hillary is untrustworthy" (post-election: unreleased tax returns, private business during State visits)
25. "Drain the swamp" (post-election: many lobbyists are now in Administration positions)
26. "Obama's failures" (Last eight years: obstruction; post-election: reconstruction ... later: destruction)
27. Robert Redford's "The Candidate" (post-election: What do we do now ? ... watch the current news)