Thousands of airport employees, fast food workers and minimum-wage earners across the country protested Tuesday in the first major Fight for $15 effort since President-elect Donald Trump's White House victory was announced earlier this month.

But a minimum wage battle that was once a mostly left-vs.-right conflict has now bled over party lines, potentially putting pressure on Trump and GOP lawmakers to raise the federal minimum wage for the first time in more than seven years.

The Fight for $15 campaign on Tuesday organized a "national day of disruption," as workers blocked roads, slowed production and protested wages they feel are unfairly low. Airport workers, in particular, turned out in droves, lining up outside of Chicago's O'Hare, the District of Columbia's Washington National and Atlanta's Hartsfield-Jackson, among other heavily trafficked airports.

Heading into Tuesday, the campaign expected protests in 320 cities involving "tens of thousands" of workers. Uber drivers were also expected to join the fray in cities like San Francisco, Boston and Denver.

"Today, working people across the country, from fast food workers to adjunct professors, are striking and demonstrating in favor of a $15 minimum wage – the largest demonstration in the history of the Fight for $15 movement," Lawrence Mishel, president of the left-leaning Economic Policy Institute, said in a statement Tuesday. "A bold proposal such as $15 is needed to lift the earnings of the bottom third of the workforce, generate robust wage growth overall and fuel economic growth."

The Bureau of Labor Statistics estimated 2.6 million Americans earned wages at or below the $7.25-per-hour federal minimum wage last year, making up 3.3 percent of all hourly workers. About 3.1 percent of all hourly white workers were paid at or below the minimum wage, while 4.3 percent of black or African-American workers and 2.9 percent of Hispanic or Latino workers were paid at or below the federal baseline.

Research is split on the economic consequences of a minimum wage hike. Some studies suggest such a raise would hurt small businesses and slow hiring. Other research suggests there's little correlation between moderate wage increases and hiring trends.

Republicans have tended to favor the former line of thinking, suggesting federal wage hikes don't make economic sense and are inappropriate at a national level. Democratic nominee Hillary Clinton and rival Bernie Sanders, meanwhile, had each argued for wage hikes as part of their presidential platforms. So given Trump's and the GOP's dominance on election night, many supporters of the Fight for $15 movement aren't optimistic about the next few years on Capitol Hill.

"Today, there is a renewed sense of urgency because of the results of the election. You all can boo. That's good," Luisa Blue, executive vice president at the Service Employees International Union, said Tuesday from Reagan National Airport. "But the underlying struggles of these workers and their need for $15 and worker organizations, the need to fight against racism, the need to fight against deportations, hasn't changed. And we are not going to back down."

But it remains to be seen whether Trump would be an obstacle to – or an advocate for – the minimum wage movement, as he has on several occasions delivered conflicting assessments of what should be done about base worker pay. In a July interview with Bill O'Reilly on Fox News , Trump said he would "leave it and raise it somewhat" when asked what he'd do with the federal minimum wage, noting that his response was "not very Republican to say."

Indeed, a Republican-led effort last year saw lawmakers effectively block voting on a bill that would have raised the federal minimum wage to $12 per hour by 2020. Minimum wage increases have typically been viewed as progressive initiatives favored by those on the left.

But in the same segment, when O'Reilly asked Trump if $10 per hour would be adequate specifically for a federal minimum wage increase, Trump indicated yes, but "we'll let the states do it." This would not be a federal minimum wage increase at all.

Trump's refusal to take a consistent and cohesive stance on the issue may have worked to his favor. More and more Republicans have jumped aboard the minimum wage hike train in recent years, dividing the base and muddying the path forward for the Republican party.

An Associated Press-GfK poll published earlier this year found that 40 percent of Republican respondents favor a wage increase, while 27 percent did not lean one way or another. Less than a third – 31 percent – opposed the idea of a wage increase. Unsurprisingly, the poll found that eight in 10 Democrats support such a wage boost.

Consider those who voted for Trump in the 2016 election. State-level minimum wage hike initiatives were on the ballot in four states: Arizona, Colorado, Washington and Maine. They ended up passing in all four states, but Republican voters were largely divided geographically.

In Colorado, there were eight counties in which 80 percent of the population or more voted for Trump. Support for Colorado's minimum wage initiative was under 50 percent in all eight of these counties, suggesting voters here wanted Trump in office but did not want to see state-mandated base wages rise.

In Maine, meanwhile, support for a minimum wage initiative was north of 50 percent in seven of the nine counties where Trump won. And in Arizona, a minimum wage ballot measure passed in 10 of the 11 counties that voted Trump.

Washington's votes were still not completely counted at the time this article was written, but of the six counties with 100 percent reporting that went for Trump, only two saw strong support for a minimum wage hike.

The 2016 Republican Party Platform indicates that "minimum wage is an issue that should be handled at the state and local level," so Trump's presidential success and the GOP's congressional sweep don't bode particularly well for wage hikes in the near future. But Trump's array of minimum wage stances has at times contradicted the GOP's official platform.

That's not to say a minimum wage increase would entirely be up to him. Minimum wage bills have historically fallen into congressional territory. But Republican constituents appear to be less opposed to pay increases than they've been in recent history.