The impending November midterm elections, in which control of both houses of the United States Congress is being closely contested, could have significant consequences for the largest foreign policy challenge currently facing the Biden administration: Russia's invasion of Ukraine.

Since Russian President Vladimir Putin ordered his troops into Ukraine in February, the U.S. and its allies, including most NATO countries, have been funneling aid and weapons into the country to help prop up the government and repel the invaders.

While the U.S. public still maintains broad support for Ukraine, and bills providing for aid have been passing with large bipartisan majorities, a vocal minority of Republican lawmakers, echoed by a number of influential voices in the broader conservative movement, have criticized the federal government, saying it is spending too much and potentially prolonging the conflict.

Pressure on US policy

Now, some experts are questioning the degree to which that minority might be able to sway U.S. policy if the party successfully seizes the House, the Senate, or both, in November.

"I think it's top of mind for a lot of people in Washington who are supportive of what we've been doing in Ukraine," Conor Savoy, a senior fellow at the Center for Strategic and International Studies, told VOA.

Savoy said a significant number of the Republican lawmakers who have voted against Ukraine aid so far, including many of the 57 who voted against a $40 billion aid package in May, have done so because of concern about a lack of oversight over the spending. But others include many self-styled populists in the mode of former President Donald Trump, who are instinctively suspicious of foreign aid spending, even when it is supported by the party's leadership.

"They don't like this," Savoy said. "They think it's money down a foreign rat hole."

While there has also been some Democratic opposition to Ukraine spending, the resistance in that party has been far smaller. Combined with broad Republican support, Democratic majorities have been able to push aid packages through.

Determined resistance

It's far from certain that things would change if the GOP takes power in Congress, given that a majority of Republicans still supports aiding Ukraine. However, it is important to remember that in Congress, a determined minority is often able to thwart the will of the majority.

A decade ago, while the Republican Party ran the House of Representatives, a core group of conservatives - the Freedom Caucus - consistently stymied their leadership's efforts to make budget deals with then-president Barack Obama, leading to government shutdowns and fears of a default by the Treasury Department.

Some observers have noted a growing rift between the Republican Party's leadership and its populist wing.

"The schism between the party's establishment Republicans and Trump-style populists raises questions about whether President Joe Biden can rely on lawmakers to continue funding the influx of U.S. military equipment to Ukraine if Democrats lose control of Congress," the website Defense News noted last month.

On the campaign trail, Democrats have used the threat of a Republican takeover scuttling Ukraine aid as a talking point.

In Ohio, Democratic Senate candidate Tim Ryan has repeatedly gone after his Republican opponent, J.D. Vance, for the latter's admission, "I don't really care what happens to Ukraine one way or another."

Conservative groups dubious

Over the weekend, the influential Conservative Political Action Conference (CPAC) posted a tweet that immediately gained broad attention because it seemed to validate Putin's claim to have "annexed" four regions of Ukraine.

"Vladimir Putin announces the annexation of 4 Ukrainian-occupied territories," the tweet read. "Biden and the Dems continue to send Ukraine billions of taxpayer dollars. Meanwhile, we are under attack at our southern border. When will Democrats put #AmericaFirst and end the gift-giving to Ukraine?"

The organization later deleted the tweet, claiming that it had not been approved by its leadership. It was replaced with one that called Putin a "madman" and his invasion of Ukraine illegal.

However, the same reluctance to continue funding Ukraine at current levels remained.

"We must oppose Putin, but American taxpayers should not be shouldering the vast majority of the cost," CPAC said.

Other conservative organizations have also expressed concerns.

"The American people are tired of the neoconservative policy consensus that demands billions of their tax dollars be spent to defend the integrity of Ukraine's border when resources and stewardship cannot be found to address our own," Russ Vought, president of the Center for Renewing America, told the website Defense One last month. "This new package will prolong a fight that lacks an American dog [pressing U.S. interest], allowing regional allies to shirk their security responsibilities yet again."

Diverting resources

On Sunday, Republican Representative Matt Gaetz, whose home state of Florida had just been ravaged by a hurricane, used Twitter to suggest that aid to Ukraine was diverting assistance from his constituents.

'Dear Congress: On behalf of my fellow Florida Man in grave need of assistance ... Just send us like half of what you sent Ukraine. Signed, Your Fellow Americans,' he wrote.

Last week, announcing her vote against a spending resolution that included more funding for Ukraine, Representative Marjorie Taylor Green tweeted, "Today, I'm voting NO on the continuing resolution to fund America's 50 states, plus America's 51st state: Ukraine. Also in the news, Vladimir Putin has just annexed a large portion of Ukraine. Are we funding Russia, too?"

Republican leaders in the House have indicated that if they take over, the general view of their caucus - including any newly elected members - will factor into their decision-making.

In remarks to reporters last month, Representative Elise Stefanik, the third-ranking Republican in the House, said, "We want to make sure they get all the briefings. I know there's concern, rightfully so, about having oversight over those dollars. I'm not going to get ahead of our members before the election, our newly elected members. It's going to be a conference decision of those new members."