The November 6 U.S. midterm elections are widely believed to be the most consequential in decades. Control of both the House of Representatives and Senate hang in the balance, and several important governors’ mansions are on the line. But in addition to these, in many ways local, contests, both the Democrats and Republicans have effectively acknowledged that this will be the first major public referendum on Donald J. Trump and his presidency since his upset victory over Hillary Clinton in 2016. The outcome will determine the balance of power in Washington for the next two years and will therefore have a disproportionately influential role, at least compared to most other midterms, in helping shape U.S. foreign policy until the next presidential election in 2020.

If Democrats win a strong majority in the House through a decisive “blue wave,” and especially should they also seize control of the Senate (although that seems unlikely), Trump’s authority, including in foreign policy, will be significantly circumscribed. If, on the other hand, Republicans not only hold the Senate but manage to retain control of the House, his administration and grip on foreign policy will be strengthened. A split decision, with Democrats winning a sizeable House majority but Republicans retaining a small but solid Senate majority, would be problematic for Trump, but would also result in the most complex power equation. It would mean that, in effect, the jury is still out on Trumpism, and the matter will be tabled until 2020. This scenario, leaving both sides feeling both vindicated and vulnerable, is entirely plausible, and indeed likely.

What’s at Stake for the Gulf Arab States

With several key Gulf Arab countries – especially Saudi Arabia and the United Arab Emirates – closely associated with the Trump administration, especially in public perceptions, many of their interests are in play and potentially at risk. Democratic control of the House would entirely transform policymaking in the coming two years. Under Trump, Republicans have enjoyed an unusual, though hardly unprecedented, monopoly on power in Washington, with both houses of Congress under their control. Trump has therefore faced very little resistance from Congress to his foreign and other policies. Legislators did buck Trump by insisting on new sanctions against Russia that he did not want and there was some institutional resistance in Congress to some weapon sales, including to Gulf Arab countries. But, overall, Trump has enjoyed a relatively free hand.

Democratic control of the House would transform that equation. Trump would need the cooperation of Democrats on a wide range of foreign-policy initiatives that involve U.S. funding or that can be blocked by legislative actions. While the Senate is better placed, in most cases, to block presidential initiatives, key House members can also take substantial action to restrict weapons sales, technology transfer, and anything involving the allocation of U.S. government funds. Moreover, Democrats would wield the chairman’s gavel in multiple House committees, and could therefore launch consequential investigations and actively help to shape the public debate on U.S. foreign policy. A number of policies would be affected by such a result, especially those involving Trump’s relationship with Saudi Arabia. Both Trump and the Saudis have greatly publicized their alignment following the strains of the era of former President Barack Obama. Indeed, the extremely close relations between the Saudi government and the Trump administration are now a prime avenue of foreign policy attacks against the president, and come at very little, if any, political cost to his critics.

Weapon Sales and the Yemen War

Weapons sales to key Gulf allies, especially Saudi Arabia and the UAE, already faced mounting opposition in Congress due to concerns regarding the Yemen war. A large group of Democrats and even some well-placed Republicans, including Senate Foreign Relations Committee Chair Bob Corker, Lindsey Graham, and Marco Rubio, have expressed growing unease about U.S. responsibility for a humanitarian crisis in Yemen that has been greatly exacerbated by the conflict. During Obama’s second term, and again under Trump, temporary holds were placed on certain Yemen war-related sales, especially 120,000 precision guided munitions that would replenish stocks expended in the Yemen campaign. A bipartisan effort to force the U.S. government to abandon any substantial cooperation with the Arab intervention in Yemen failed, but garnered substantial support.

Yet concern regarding Yemen continues to develop, and anger at Saudi Arabia is now focusing on the murder of Saudi journalist Jamal Khashoggi on October 2 at the Saudi consulate in Istanbul. There is a widespread desire in Congress to register U.S. disapproval of the Khashoggi murder that dovetails with mounting anxiety about the situation in Yemen, suggesting that another legislative effort to restrict U.S. involvement in the war might meet with success, especially should Democrats hold majorities in either or both houses of Congress. This may also threaten certain weapon sales, at least with significant holds, delays, and legislative caveats. Several pending sales to Saudi Arabia potentially fall in this category, including the precision guided munitions and the Terminal High Altitude Area Defense anti-missile defense system. THAAD also involves potential significant technology transfer in which U.S. national security and Israel’s qualitative military edge could be invoked to delay or block it. The same applies to UAE efforts to purchase the F-35 fifth generation fighter jet, which could also face Yemen-related difficulties.

By investigating hot-button issues such as the humanitarian crisis and civilian deaths in Yemen, the Khashoggi murder, or other human rights concerns, empowered congressional Democrats could seek to sabotage Trump’s close relations with Saudi Arabia, and even the UAE, for partisan political benefit while ostensibly asserting U.S. and Democratic Party values.

Iran

Iran has also become a partisan political issue between Republicans and Democrats. Trump’s incessant attacks on Obama’s Iran policies, particularly the Joint Comprehensive Plan of Action nuclear agreement, which he withdrew from earlier this year, reveal the stark divide on Iran between Republicans and Democrats. Most Republicans have welcomed Trump’s “maximum pressure” campaign against Iran, but many Democrats condemn it as irrational and misguided, and compare it unfavorably to the nuclear deal, which they broadly supported. Most Iran-related policies are not dependent on congressional action and can be ordered by the executive alone. But a White House that enjoys legislative support will be much more authoritative than one that is constantly bickering with the House, or the Senate, over sanctions and other pressure against Iran.

Therefore, Democratic control of one or both chambers of Congress would significantly complicate Trump’s “maximum pressure” campaign against Tehran. European countries seeking to keep the nuclear deal going in spite of U.S. opposition would suddenly find themselves with empowered partners in Washington. This could reinforce the feeling in European capitals and especially Tehran that the wisest approach would be to wait out the Trump administration in preparation for a more amenable Democratic-dominated government following 2020. If, on the other hand, Republicans retain majority control of all of Congress, the impression will grow that U.S. policy has decisively turned the corner, and that mounting sanctions and other pressure against Iran and U.S. allies in Europe on these issues will be the U.S. approach into the foreseeable future. Given the extent to which a pressure campaign involves shaping perceptions and psychological warfare, the impact of the elections’ outcome on the efficacy of Iran policy might be substantial.

Other Gulf-Related Policies

A range of other Middle East policies may be affected by the elections’ outcome. The Trump administration appears to be finally coalescing around a new Syria policy based on maintaining U.S. force structures in eastern Syria and cooperation with Turkey and Russia to ultimately restrict Iran’s influence in the country. It’s unclear whether Democrats substantially object to this policy, especially given Israel’s strong interest in a robust long-term U.S. presence in Syria, and therefore this approach might even be bolstered by a Democratic House.

Support for Israel among Democrats is strong, so there has been very little partisan opposition to Trump’s major swing toward Israel by moving the U.S. Embassy to Jerusalem, cutting off ties to the Palestine Liberation Organization, and defunding virtually all U.S. aid to the Palestinian Authority and agencies caring for Palestinians. There has similarly not been a partisan edge to varying opinions in Congress about the boycott of Qatar. Military aid to Egypt, though, could face objections similar to those regarding weapon sales to Saudi Arabia, based on human rights considerations.

Democrats and some Republicans may also continue to push back on the idea of the United States playing a leading role in helping Saudi Arabia develop a domestic nuclear industry, including the enrichment of uranium mined in the kingdom and the reprocessing of plutonium. In the wake of the Khashoggi murder, a bipartisan group in Congress has been pushing for the United States to pull back from these negotiations. However, Riyadh would probably be able to obtain most, if not all, of the required technology from other suppliers. Nuclear negotiations with Saudi Arabia are an excellent illustration of the chasm in priorities separating two U.S. foreign policy visions. Most Democrats and some Republicans want to use foreign policy to achieve broad and consistent policy goals based on the promotion of an international rules-based order and would therefore not want to assist any Saudi nuclear energy project without “gold-standard” commitments from Riyadh. Trump and his allies hold a more mercantile view that would suggest that if there are competitors willing to take the contracts, there is no good reason for the United States cheating itself out of a profit for an effectively empty gesture.

A Referendum on “America First?”

The midterms may help clarify whether this “America first” Trumpian view is gaining or losing traction with the public and, therefore, demonstrate its long-term prospects as a driving force in U.S. foreign policy. But a split decision leaving Democrats in control of the House and Republicans with a small edge in the Senate seems to be shaping up. That would decide little and postpone a more thorough reckoning until 2020. Many Arab governments in the Gulf will probably be rooting for a strong Republican showing, but history shows they can also work well with Democrats. However, the willingness of some Gulf countries, particularly Saudi Arabia, to allow themselves to become so closely associated with Trump and his policies in the public mind has made their interests more of a partisan wedge than they could, or logically should, be. And, unlike Israel, Gulf Arab countries don’t have a strong body of independent support in the U.S. system to defend them from any resulting partisan attacks. Whatever the outcome of these particular elections, reaching out to Democrats is advisable for those Gulf Arab countries that have become too closely associated with the Republicans in the Trump era for their own long-term interests.