A demonstrator holds a sign during a Fair Maps rally outside the US Supreme Court, in Washington, DC, US. REUTERS/Brendan McDermid

Recent rulings by the US Supreme Court on gerrymandering and campaign finance have altered the legal landscape for elections. As the campaign for the midterms intensifies, Global Insight examines the implications.

The battle for control over the United States Congress will probably be closer than favourable polling for Democrats would suggest after the Supreme Court’s conservative majority handed Republicans key wins on campaign finance and gerrymandering – the redrawing of electoral maps by a state legislature in an attempt to maximise the number of seats won by a certain political party.

Polls show Americans are largely unhappy with Donald Trump’s performance as president and appear poised to hold him to account in November’s national midterm elections.

It’s almost an immutable law in US politics that the party that won the White House will typically lose seats in Congress two years later. Since the Second World War, the incumbent president’s party has lost seats in Congress in every midterm election, with only two exceptions in 1998 and 2002 due to unusual circumstances.

President Trump now faces a repeat of what happened in his first term as president when Republicans lost dozens of seats in the House in 2018. Trump’s approval rating among Americans has been trending downwards since he took office, hovering at around 40 per cent on average in July.

Republicans presently hold a narrow majority over Democrats in the House of Representatives. All 435 House seats will be up for election, but only 40 districts are expected to see competitive races.

A gerrymandering arms race

This election cycle has seen a move by Republican-controlled state legislatures, beginning with Texas, to redraw their congressional maps to gain an advantage in November. The Supreme Court and state courts played key roles.

The gerrymandering scramble began in summer 2025 when President Trump asked the Texas Governor Greg Abbott to redraw the state’s voting maps.

Trump told White House reporters that he expected Republicans to get five more seats as a result. ‘And there could be some other states where we’re going to get three or four or five. Texas will be the biggest one,’ he said.

States typically redraw their congressional and state legislative maps every ten years to account for population changes. President Trump broke the norms of US political cycles by urging states to revise their maps again mid-decade with the explicit goal of taking seats in Congress away from Democrats.

Texas had 25 Republicans and 13 Democrats in its US House delegation. A new voting map pushed through the state legislature by Governor Abbott – all else being equal – would probably shift the delegation’s balance to 30 Republicans and only eight Democrats.

President Trump has pointed to Democrat-controlled states as having already been gerrymandered and said that, given the vote share he received in Texas in the 2024 election, Republicans are ‘entitled’ to more seats in the state.

The Supreme Court allowed Texas to go forward with the plan despite a finding by a federal appeals panel that the redistricting had been not just partisan, but racially motivated. ‘[I]t was much more than just politics. Substantial evidence shows that Texas racially gerrymandered the 2025 Map,’ wrote Justice Jeffrey Brown, a Trump appointee, in a ruling striking down the new lines.

Abbott appealed to the Supreme Court, which reversed the lower panel’s ruling in a summary opinion by Justice Samuel Alito – rejecting the finding of racial motivations.

Justice Elena Kagan wrote in dissent that the new map was ‘slanted toward Republicans’ and ‘violated all our oft-repeated strictures about the use of race in districting’.

Other Republican-controlled states quickly followed Texas’s lead. In response, Democrat-majority California undertook a partisan redistricting after voters approved a ballot initiative, potentially flipping five seats away from Republicans. A similar attempt by Democrats in Virginia was blocked by the state’s highest court on process grounds.

A key US Supreme Court judgment came toward the end of its just-concluded 2025–26 term with an opinion on a redistricting and voting rights case in Louisiana.

In Louisiana v Callais, the Court’s conservative majority struck down a Louisiana map that had created a second majority-Black congressional district by a 6–3 vote. Black voters constitute roughly a third of the state’s voting population. The new map consolidates two Black-majority districts into one and seems set to yield one new congressional seat for Republicans.

The practical effect of the Court’s ruling of 29 April was to leave states with broad freedom to redraw voting districts to maximise partisan gain, even if the new maps disadvantage minorities in ways that previously would have been disallowed under the Voting Rights Act.

In June, in a four-page unsigned order, the Supreme Court cleared the way for Alabama to use a congressional map that lower courts had found to be racially discriminatory. Justice Sonia Sotomayor, writing in dissent, warned the Court’s majority ‘disregards both democratic values and the rule of law’.

‘The Supreme Court rightly recognized that its recent decision in Louisiana v Callais fundamentally changes the legal landscape,’ said the Alabama State Attorney General Steve Marshall in a statement. The ruling ‘affirms that Alabama’s elected representatives, not federal judges, have the primary authority to draw the maps under which Alabamians choose their own leaders,’ he added.

In March, the Supreme Court summarily blocked an effort by Democrats in New York state to redraw maps in their favour. New York’s proposed district amounted to ‘unadorned racial discrimination’ in favour of ‘minority voters’ and therefore an ‘odious’ violation of the Fourteenth Amendment’s Equal Protection Clause, Justice Samuel Alito wrote.

Reacting to the Republican gerrymandering and Supreme Court rulings, Democrats in New York and six other states plan to overhaul their voting districts for the 2028 election, setting up a future battle.

The net result of redistricting drives could see Republicans gaining as many as 16 House seats through redistricting in Texas, North Carolina, Ohio, Missouri, Florida, Louisiana, Alabama and Tennessee. These will probably be offset by five Democratic gains in California and Utah, according to an analysis by The Cook Political Report in Washington, DC. A best-case scenario for Democrats would see Republicans gaining as few as two seats from redistricting.

Either way, given the very narrow majority in the House that the Republicans hold and the political headwinds they face, redistricting probably won’t be enough to prevent them from losing control of the chamber.

In the battle for the Senate, where Republicans presently hold a six-seat majority, a key factor will be money as candidates face the daunting costs of funding statewide races. Of the 35 Senate seats up for election in this cycle, nine races – in states ranging from Alaska to New Hampshire – will be the most competitive.

‘A rule needed to protect Democracy’s integrity’

In June, the Supreme Court struck down a federal law that limited how much money political parties can spend in coordination with individual candidates.

In the case National Republican Senatorial Committee (NRSC) v Federal Election Commission (FEC), the Court ruled 6–3 that the post-Watergate amendments made in 1974 to the Federal Election Campaign Act, which limited party spending in coordination with congressional candidates, violate the protection of free speech under the First Amendment and were therefore unconstitutional. ‘All political parties’ can now ‘participate more freely and compete more fully in the political process,’ Justice Brett Kavanaugh wrote in the majority opinion.

Writing in dissent, Justice Kagan said the majority decision ‘jettisons a rule needed to protect our democracy’s integrity’. Individual contributions to candidates are limited to $7,000 per election cycle. Lifting the restrictions on how much parties can spend in coordination with candidates effectively circumvents those limits, Kagan argued. ‘There is no point to the $7,000 base limit if a deep-pocketed donor can spend hundreds of thousands more to pay for campaign expenses,’ she said.

Republicans tend to benefit more from larger campaign contributions to party committees given by wealthier donors. Democrats tend to raise more in smaller donations to individual candidates.

Illustrating the differences, the Republican National Committee had $125m in cash on hand as of 31 May, while the Democratic National Committee had less than $15m, according to reports filed with the FEC. President Trump’s MAGA Inc political fund, for which there’s no Democratic Party equivalent, had $382m in cash, according to FEC data.

Offsetting these Republican advantages, Democratic candidates in key states have been raising more from individual donors. In Ohio, for example, Democratic challenger Sherrod Brown leads incumbent Republican Senator Jon Husted in fundraising by $16m to $8m. Under the old limits, state and national Republicans could have spent about $2.4m in coordination with Husted. Now they can support him with funds limited only by how much cash the party can raise and stockpile.

‘If parties are allowed to utilise their money with direct assistance to their candidates, that might help those campaigns financially – particularly the Republican Party, which currently has a significant fundraising advantage,’ Jan Baran, a partner at law firm Holtzman Vogel in Virginia who represents Republicans in election matters, told Global Insight earlier in 2026.

The Supreme Court has previously ruled that party organisations can spend unlimited amounts independent of any candidate’s campaign. This new judgment means the Republican Party’s national fundraising arms can pump more money directly into the race in coordination with a candidate such as Husted – a pattern likely to be replicated across key battleground states and House districts.

The NRSC ruling follows a growing line of judgments led by conservatives on the Supreme Court under Chief Justice John Roberts that sharply narrow the ability of Congress to curtail money in politics. These other rulings include Citizens United v FEC in 2010, McCutcheon v FEC in 2014 and FEC v Ted Cruz for Senate in 2022.

The bottom line is that President Trump’s low public approval implies a Republican loss of about 37 seats in the House. Gerrymandering could trim these losses by five to ten seats, still leaving Democrats a clear path to control the House. The battle for the Senate will be tight, with Republicans gaining what could prove to be a decisive money advantage from the Supreme Court’s ruling.

William Roberts is a US-based freelance journalist and can be contacted at wroberts3@me.com