Jeff Greenfield is a five-time Emmy-winning network television analyst and author.

For Democrats looking to win back a piece of national political power, the House is where the heart is. With a gain of 23 seats needed for control, and the Cook Political Report listing 29 Republican seats at risk (and only three imperiled Democrats), it’s a plausible political target. Last week, Barack Obama’s political action committee, Organizing for Action—granted, with a highly unimpressive track record in the past two midterms—announced it would throw its energies into some two dozen House races with what a spokesman called “an all-hands-on-deck movement.”

But if the goal is to thwart the wholesale, radical changes in policy that President Donald Trump’s administration is pursuing, the House is the wrong target. It’s the Senate that has been the most significant political player of the past four years. Although the president has made himself the obsessive focus of friends and foes, it was the Republican capture and retention of the Senate in 2014 and 2016 that was and is the key to what Trump has wrought. To understand why, imagine what the political terrain would have looked like with the Senate in Democratic hands.


Republicans took the Senate in 2014 when popular Democratic incumbents in red and purple states (West Virginia, Iowa, Montana) retired, and Republicans avoided nominating wingnut candidates in other states (Indiana, Colorado, Missouri) that had cost them four or five seats in 2010 and 2012. With that control, Majority Leader Mitch McConnell was able to pull off a singular triumph: blocking President Obama’s nomination to replace the late Supreme Court Justice Antonin Scalia with D.C. Circuit Chief Judge Merrick Garland with almost a year left in Obama’s second term.

With a Democratic Senate, Majority Leader Harry Reid likely would have done exactly what Mitch McConnell did in 2017—abolish the judicial filibuster, and elevate Garland (rather than Neil Gorsuch) to the high court. If Reid had stayed his hand, his successor, Chuck Schumer, might have exercised a “thermonuclear option” of his own: In the 17 days between the start of the new Senate and Donald Trump’s inauguration, Obama could have renominated Garland and a Democratic Senate could have confirmed him. The fallout would have been huge, but Schumer could have pointed to McConnell’s yearlong obstructionism, and the fact that Trump won 3 million fewer votes than his rival.

OK, put that fantasy aside. Instead, look at what would have happened with Trump in the White House and Democrats in control of the Senate. Gorsuch’s confirmation battle becomes much tougher, even if his genial demeanor might have convinced enough Democrats that he was not Scalia on steroids. More broadly, there is no way that the Senate Judiciary Committee, under the leadership of Dianne Feinstein, would elevate a record number of judges—with views that range from highly conservative to fringe—to federal courts. (One Trump nominee would not agree that the landmark school desegregation case Brown v. Board of Education was rightly decided.) Nor would Feinstein have ignored, as Senator Charles Grassley has done, the traditional “blue slip” power of senators to block the appointments of judges from their home states.

When Trump supporters point to the president’s achievements, they cite his judicial choices, and for good reason. More than any other power (except—perhaps—the ability to wage war), a president’s ability to reshape the federal bench—a power that lasts decades beyond a presidential term—is the most potent. Put Democrats in the Senate these past two years and that power would have been significantly weakened.

But the significance of the Senate reaches beyond control of the bench. What is Trump’s most significant legislative victory? It’s the $1.5 trillion tax cut, with its many comforts to the comfortable. That bill passed by a 51-48 margin. With Senator Ron Wyden as chairman, not only does that tax bill not pass, it does not leave the Finance Committee in anything like its present form. The Republicans would also have failed to repeal the Affordable Care Act’s individual mandate for health insurance.

The president’s Cabinet requires the advice and consent of the Senate (and only the Senate). With Democrats in power, a host of Cabinet appointees—from Betsy DeVos at Education to Scott Pruitt at the Environmental Protection Agency to Mick Mulvaney as the budget chief—likely go down to defeat. Another Cabinet member who might have lost the confirmation battle? Jeff Sessions as attorney general. With a different appointee, the battle over the charges of Russian collusion in the campaign and obstruction of justice would have taken on a radically different shape. Maybe Robert Mueller would still be toiling away at WilmerHale.

With Democrats in control, the investigative power of the Senate could turn an unsparing spotlight onto the behavior of the Trump administration, very much including the first family. There’d be a more or less permanent forum to probe conflicts of interest, like the trademark grants given by China to Ivanka Trump as the president reached out to save a Chinese telecom giant blacklisted by the Department of Commerce.

This thought exercise in imagining what a Democratic Senate might have done over the past four years underscores why control of the upper house of Congress will matter so much more for the rest of Trump’s presidency than what happens in the House. Yes, a Democratic victory in the lower chamber would slow whatever is left of Trump’s domestic agenda. Yes, the House has its own considerable power to investigate wrongdoing in the executive branch. Yes, it’s the chamber that begins the impeachment process. But if Republicans hold the Senate—and the platoon of endangered Democratic incumbents suggests that’s likely—the most significant elements behind Trump’s victories will remain untouched.

The reshaping of the federal judiciary would remain firmly in Republican hands, and with it, the increasing likelihood of new Supreme Court appointments that would lock in conservative control of the court for decades. Trump’s next round of Cabinet appointments would win confirmation, no matter their views on immigration policy, labor law, environmental protection. On foreign policy, where the Senate holds the lion’s share of legislative power, there would be no institutional challenge to the president’s impulses save an occasional rhetorical sigh of unhappiness from the Republican majority.

So around midnight on November 6, Democrats may be in a party mood if the electorate gives them control of the House. But if the Senate stays in Republican hands, the celebration will look very different in the cold light of day.