Presidential primary elections can only be delayed for a limited time. [View all]
In many states, that election is also an election with many other positions on the ballot. In Wisconsin's case, some of those other elections affect positions in which the newly-elected official takes office soon after the election. So, that election cannot be delayed.
In other states, primaries have been delayed, but the issues with the COVID-19 pandemic will still be issues at the time the delayed election is held. In any case, elections must take place before the Party conventions later in the Summer, so that delegates to the convention can be allocated. The Democratic Party has delayed its convention until August, and may have to hold it virtually, if the pandemic does not let up.
Every state allows for absentee balloting. Some make that easy; others still have antiquated rules regarding absentee voting. Some states are expanding voting by mail, specifically due to the current health crisis. In any case, primary elections always have lower turnouts than general elections. Results are always from those who do vote, and that will be the case in 2020 as well.
If your state's primary is still to be held, please request and absentee ballot and vote, as soon as you can. Make your vote count. The elections will be held. The Party Convention will take place, in one form or another. A nominee for President will be chosen for the Democratic Party. Those things will happen. So, please find out what you need to do in your state to vote, and do that thing.
It's simple. But, the primaries will take place. The General Election will take place. You can choose whether to take part or not. I recommend that everyone participate. It's important.