Back in February, Treasury Secretary Steven Mnuchin predicted American workers and businesses would be enjoying tax cuts by now. “We want to get this done by the August recess,” he said on Feb. 23. “We’re primarily focused on a middle-income tax cut and simplification for business.”

Congress will soon return from its August recess with tax reform still months away. The Trump administration obviously got off to a halting start, with immediate court battles over Trump’s hastily imposed immigration ban and a divisive, failed effort to repeal the Affordable Care Act. Mnuchin and other top administration officials, meanwhile, have ratcheted back their promises for tax legislation, perhaps the most important Trump initiative for financial markets.

In April, Mnuchin said the Trump administration would release a tax plan “very soon,” while acknowledging it probably wouldn’t pass by August. There is still no Trump tax plan, however, and there may never be one. Instead of pushing its own plan, the White House now seems set to rely on Republicans in Congress to formulate a plan from the various GOP proposals that have been kicked around for years.

Mnuchin now says he hopes a tax bill will pass by the end of the year while leaving some wiggle room for that to slip into next year. President Donald Trump himself will start talking up tax reform this week, during a visit to Missouri. But previous Trump efforts to play up important priorities, such as “Infrastructure Week,” “Technology Week” and “Made in America Week” have been upstaged by various Trump controversies, including Trump’s own attacks on allies and critics alike. It would fit the profile if Trump undermined his own effort to rally support for tax cuts with an ill-timed Twitter fusillade or a fratricidal attack on should-be GOP allies.

How will investors react to tax cuts

If Congress actually passes a tax-cut bill, and Trump signs it, it probably won’t matter that Mnuchin was naïve about the bill’s timing and whether it originated in Congress instead of the White House. But markets won’t wait forever, and if it turns out Republicans have over-promised, an adverse reaction is likely. “It’s a mystery to us why the White House keeps raising expectations for tax reform,” Greg Valliere of Horizon Investments wrote in a recent note to clients. “It simply sets expectations too high, which means a disappointment is inevitable.”

Investors expect Congress to spend September negotiating spending bills that must go into effect by Oct. 1, along with an increase in the government’s borrowing authority. If those pass without high drama like a government shutdown or a threat to default on some U.S. debt payments, Congress could take up tax reform in October. It’s technically possible to pass a bill by the end of the year, though most forecasters think it won’t happen till 2018.