If Thomas Jefferson rose from the grave, he would be shocked that major portions of the Constitution are still in play.
It is time to have a unicameral Congress. There would still be Republicans and Democrats and other parties. These would have a six-year term limit, as would the president. However, if the members of Congress cannot agree, there would be a parliamentary vote for a new president. If members of Congress cannot form a coalition government because of no majority of the public, then the next highest member would become president. This is much like the English and Israeli constitutions. This assumes there would be more than two parties.