How could this shake out in a Clinton-Trump election? Let’s set aside national security and terrorism, and only consider the legislative agenda that might have a significant impact on the economy and markets.
Trade: There is a difference between the two candidates. Trump wants to roll back the North American Free Trade Act and block the unratified Trans-Pacific Partnership. Clinton supported Nafta and initially backed the TPP, but she now seems to have changed her mind.
Taxes: There are wide differences between these two on tax policy. Trump wants tax cuts for the wealthy while Clinton seems to favor raising them.
Capital Repatriation/Tax Holiday: Both candidates support some form of “tax holiday” to bring the $2 trillion or so of offshore corporate profits stashed overseas back to the U.S. But the devil is always in the details, and the specifics will matter a great deal.
Infrastructure: Not counting the wall that Trump wants at the U.S.-Mexico border, both seem to favor spending on infrastructure.
Appointees: Each candidate is likely to appoint very different people to key positions at the Supreme Court, the Securities and Exchange Commission, the Federal Reserve and other important agencies. Their staff advisers are likely to be very different as well.
Much of the above requires the cooperation of Congress, something that can't be guaranteed based on recent history.
So while the winner in November will be consequential to markets and the economy, he or she might be less so than many voters and investors imagine.