Foreign policy

Normally, foreign policy is not a prominent issue in US presidential elections — let alone the midterms, which tend to focus on national and local topics. But these are not normal times. Foreign policy played an outsize role in the presidential race that Donald Trump won in 2016 and could be a factor again in the elections on November 6 — albeit in an indirect way.

"What the midterms usually are is a reflection of presidential popularity," said Trevor Thrall, a foreign policy scholar at George Mason University and the Cato Institute. "Trump's foreign policy efforts have been pretty unpopular on average with the American public — that's what most of the recent polling shows — and that had a depressing effect on his popularity."

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While foreign policy as an individual issue will likely not be a key election focus, the outcome of the congressional election could, however, impact the Trump administration's conduct of foreign affairs in various ways. Should Democrats wrest the Senate from Republican control, which is currently deemed unlikely but not impossible, it would give them significant sway over foreign policy.

Since Senate approval is required for executive branch nominations and international treaties, Democrats could block the appointment of foreign policy officials and put the brakes on trade agreements, a cornerstone of Trump's political agenda, and other international accords. That's why, for Trump and Republicans in Congress, losing the Senate is a nightmare scenario: It would give Democrats a strong tool to push back against the White House and its fairly unconstrained foreign policy machinations to date.

But even if Democrats only win back the House of Representatives from Republicans, a result seen as likely but not certain, they could still influence Trump's foreign policy, although to a much lesser extent than if they captured the Senate.

"In terms of hearings and public discourse, that will change quite markedly if Democrats take control of the House, because there would be committee investigations into administration actions across the board, including administrative changes on immigration enforcement," said Frances Lee, a congressional scholar at the University of Maryland.

A probe into the Trump administration's crackdown on undocumented immigrants could be one consequence of a Democratic-led House. Another would surely be the ramping up of existing investigations and the possible launch of fresh probes into the Trump campaign's connections with Russia in 2016.

None of this would change the direction of Trump's foreign policy. But it would make it a lot more difficult and time-consuming for the president to carry out his policies, which could lead him to assess whether advancing any specific foreign policy goal is worth the fight and the political price he might have to pay to push it through Democratic roadblocks in Congress.

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Often overlooked, however, is the unusual change of practically all foreign policy leadership positions in Congress after the midterms. The head of the Foreign Relations Committee in the House of Representatives, Republican Ed Royce, is retiring, as is his counterpart in the Senate, Republican Bob Corker. House Speaker Paul Ryan, who in that position has a key role in congressional foreign policy, is also calling it quits. Finally, the next head of the Senate's Armed Services Committee, an influential post long held by the late John McCain, Congress' leading voice on foreign policy, will also be determined by the midterms.

Domestic policy

Just as a Democratic takeover of one or both chambers of Congress would allow the opposition to slow down or block Trump on foreign policy, they could do the same on domestic policy — but much more forcefully. That's because the constitution allows Congress a lot more input into domestic policy than into foreign policy, which is generally the remit of the executive branch.

A Democratic House would spell the end to any Republican hopes of fully eliminating former President Barack Obama's health care reforms. It could also hamper GOP efforts to slash federal regulations or social benefits or launch another round of tax cuts.

And on a very basic level, Democratic control of the House would force Trump to deal with the opposition party in a much more measured manner than he has so far. That's because he would need the Democrats for the mundane-seeming but crucial tasks of keeping the government open or raising the debt ceiling.

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While that suggests the president would be forced to strike a more cordial tone and reach out to the Democrats, such conventional thinking does not necessarily apply to Trump. He might instead opt for an even more confrontational course, in the hopes of riling up first his base and then national sentiment against the Democrats. Should that happen — and judging Trump's behavior so far, it's a distinct possibility — it could lead to an even more toxic political climate.

2020 census

Beyond the outcome of races for Congress in Washington, the results of elections for state legislatures and governors are also key for the upcoming US census in 2020.

The census, conducted every 10 years, is the foundation upon which voting districts are realigned. In what some view as an arcane aspect of the US political system, legislators in many states can essentially carve out voting districts that favor their party.

Whoever wins control of state governments this year will determine who gets to shape voting districts for the next presidential election in 2020, and beyond.

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