Or you can use public money to fund democratic party allies and political action groups. Here in NY ACTUAL PARTIES ON THE BALLOT get public money straight from Albany, however ONLY left leaning parties. An example is the "Working Families Party."
https://nypost.com/2018/04/15/working-families-party-might-regret-endorsing-nixon/
Now that they are endorsing Andy Cuomo's primary challenger, Cynthia Nixon, Andy is pulling their funding and threatening to trigger an IRS audit LOL