Step 1. Get elected.
Step 2. Convince a friend that they should really establish an organization to fight homelessness.
Step 3. Impose a gross receipts tax to fund fighting homelessness, structured as financial support for "non-profits" with an aligned charter.
Step 4. Leave office and serve on the board of the organization your "friend" established.
End result: you've essentially elected yourself a salary paid for out of the communal treasury. The "let's just throw money at the problem" type of mindset is especially susceptible to supporting these taxes. They see the problem and obviously want to support solving it but don't follow up on the flow of money.
IMO politicians should be required to be actively performing civic duties to be getting paid by tax money. And all taxes should default to being (or be required to be) repealed after a fixed term. The people must elect to re-impose the tax based on their perception of whether it was effective or not.