The main issues going forward are going to be:
Illegal immigration: now that the borders are basically open, and we have record numbers of people coming across (and being released even if they are caught), this has become a big political issue. It is a massive crisis in places like Chicago, where migrants are sleeping in police stations, school gyms, and are now being put into tent cities in Chicago neighborhoods. There was a 72% increase in individuals arrested after crossing the border who are on terrorist watch lists in 2023. Drugs are pouring over the border. People are upset over all of this, and refuse to be gaslit by Democrats who say there isn't any problem, or that they aren't engaging in demographic replacement efforts, or importing voters (when Democrats literally say among their own people that they are doing this--that replacing white people is good).
Inflation: is still not under control, and prices don't come down when inflation eases. Homes, cars, and even food are still expensive. There isn't a lot the next president can do about this, but the public is fed up with out-of-control spending by both political parties, which fuels inflation. And again, voters are not going to be gaslit by Democrats who falsely claim that all the inflation is due to a few big companies price gouging --no one believes that nonsense.
Ukraine War: many voters are tired of this conflict and want it over. We have our own problems, and cannot afford to send billions to Ukraine. Likewise, voters worry about escalation.
Crime: is at record levels in many American cities. Remember when Clinton ran on getting crime under control and hiring lots of police? or the crime bill? Now Democrats run on defunding police departments, eliminating cash bail, and legalizing narcotics while allowing people to camp in the streets. Americans are fed up with the crime --this will be an issue in 2024.
Biden's age and competency: Democrats will run Biden from his basement next year, keep him from conducting press conferences or making public statements. He will continue to decline while a general chaos spreads through the country. The GOP is going to really focus on this issue.
Trump's legal woes and general personality: this will be an issue, but it is hard to say how big of one. If convictions are handed down, and Trump is arrested, or his name is pulled from ballots, or he is disqualified from running in the general election, it will be complete chaos.
Smaller issues are taxes, some of the culture war stuff, etc.