Tulla, the strength of the Dow is largely irrelevant in today's market. As you may know, the Dow is an index that is not tied to market capitalization of its 30 component companies, but instead reflects gains or losses in stocks based on their absolute price. The S&P 500 is the real index that we follow because movement is tied to market capitalization, meaning that a $3 move in Apple means a lot more than a $3 move by the 500th largest move in the index.
The markets are largely discounting mechanisms in the short-term, meaning that they anticipate (sometimes incorrectly, but usually not) upcoming news. The markets have rallied largely on the basis of Trump's easing of regulations and lower tax rates, both of which are huge positives for most businesses. However, after having no economic policy for the previous eight years, other than artificially low interest rates, much risk has been built into the economy; an example of this is all of the junk bonds that will be coming due over the next 2-3 years. Companies were able to capitalize on the artificially low interest rates and float bonds that had lower-than-normal yields, yet still attracted buyers. As these bonds mature, many companies might still, in spite of an improving economy, not have enough cash flow to make payments. So, instead, they will roll the bonds over. The only problem is that rates could be higher, causing the companies to take on more debt than they did in the past.
This is why the impact of presidents' policies are often felt years down the road. Trump has to figure out a way to navigate around this. As he says, he inherited a mess. However, that mess is why he got elected, so it's up to him to get it done, same as Obama never would have won had it not been for Bush and his wars and less-than-ideal management of the economy, although the Clinton Housing Bubble handcuffed Bush, without a doubt.
To me, late 2018-early to mid 2019 is going to be a potential minefield for Trump. That's when things could get interesting on the downside. The bull market can't go on forever, large amounts of junk bonds will be due, and, if the economy is growing at 4% (not certain), interest rates will be higher. At some point, a greater-than-20% correction will happen. Could it turn into a 40-50% bear market? Trump could well be a one-termer if the timing of this is correct. Dems will celebrate, but you have to be careful what you ask for, as there are not really any good candidates on their side, unless Howard Schultz somehow throws his hat into the ring. I bring this up because guys like him see that Trump can win, so they think they can do the same. The next ten years are definitely going to be interesting.