(CNN) - Since Ronald Reagan was elected president in 1980, the Republican coalition has revolved around a delicate but durable balancing act. The ongoing drive to complete the GOP's tax bill will test whether that balance can endure under the heightened stress Donald Trump's presidency is imposing on it.
Over roughly the past 40 years, the GOP has pursued a two-track approach toward building its electoral coalition.
First, Republicans have consistently targeted the cultural conservatism -- and often the racial resentments -- of the blue-collar, evangelical and rural whites who are most uneasy about the social and demographic changes remaking American life. Simultaneously, in the name of promoting capitalism and free enterprise, the party has targeted its economic agenda primarily at the priorities of the wealthiest earners and business.
To a far greater extent than his iconoclastic rhetoric as a candidate suggested, Trump in office has closely followed that twin path. Yet he has complicated this balance nonetheless by intensifying the pressure on each side of the fulcrum.
Compared with earlier Republican leaders, Trump has far more explicitly appealed to racial resentments -- from his campaign trail attacks on Judge Gonzalo Curiel to his defense of the white supremacists marching in Charlottesville, Virginia, to his tweets last week describing LaVar Ball, the African-American father of one of the UCLA basketball players accused of shoplifting in China, as an "ungrateful fool."
From the other direction, Trump and Republican congressional leaders have advanced an economic agenda that tilts more lopsidedly toward the top than earlier generations of GOP policy-making.
Past Republican economic plans -- like the tax cuts passed under Presidents Reagan and George W. Bush -- might have channeled more of their benefits toward the wealthy than to the middle -- and to working-class voters drawn to the party largely on cultural grounds. But the congressional GOP, with Trump's acquiescence, now has advanced proposals that actually impose costs on many middle- and upper-middle-class households to fund its benefits for the wealthy.
That pattern was evident in the GOP's health care bills, which sought to strip coverage from millions of blue-collar and rural whites at the core of the GOP base while repealing taxes imposed under the Affordable Care Act that affected only the highest-earning taxpayers. Many of Trump's deregulatory moves, such as his attacks on the Consumer Financial Protection Bureau, create a similar dynamic of loosening oversight of business while exposing working-class consumers to greater risk.
This aggressive upward redistribution is most explicit in the tax plans moving through Congress. The Tax Policy Center, a joint project of the Urban Institute and the Brookings Institution, recently calculated that by 2027 half of all taxpayers would pay more under the Senate Finance Committee plan heading soon toward a floor vote.
That includes nearly three-fifths of households just above and below the median income -- and fully two-thirds of the middle-class households in the center of the income distribution. Even a clear 54% majority of the families in the upper middle class (those with earnings between the 80th and 90th percentile of all households) would face higher taxes under the bill. Meanwhile, 83% of families in the top 1% of earners would receive tax cuts that average over $42,000.
Trump needs votes from critics of his racial belligerence
As a legislative strategy, this mix of social conservatism, racially infused nationalism and trickle-down economics has mostly held together under Trump, though not without bumps. On the key votes to repeal the Affordable Care Act and cut taxes, defections among House Republicans came mostly from legislators in swing suburban districts where Trump's style is unpopular.
But even those dissents from inside the party were not too widespread. And the GOP leadership held nearly unified support from representatives in blue-collar districts that saw fewer direct gains under the plans but where Trump's cultural and racial belligerence is more popular.
In the Senate, the pattern has been similar. The ACA repeal effort held support from senators representing blue-collar states that faced big coverage losses under the plan, including Ohio, Wisconsin, Pennsylvania, West Virginia, Arkansas, Kentucky and Nevada. Almost all of those senators appear certain to support the tax plan too.
The fatal healthcare defections came from three moderates who have chafed at Trump's personal style: Sens. John McCain of Arizona, Lisa Murkowski of Alaska and Susan Collins of Maine. But even on the health vote, most senators who expressed the greatest public misgivings about Trump's overall demeanor, and specifically his appeal to racial resentments, provided him their votes.
These critics who did not break with the White House include Sens. Lindsey Graham of South Carolina, Ben Sasse of Nebraska, Bob Corker of Tennessee and Jeff Flake of Arizona. With opposition unlikely from Republicans representing blue-collar constituencies -- even though the plan offers them few benefits -- the tax bill's fate will probably turn on whether most of the Senate Republicans uneasy with Trump's cultural and racial agenda continue voting with him to support the top-down economic agenda.
The cost of Trump's gamble
The electoral future is less certain for this marriage of top-down economics and bottom-up cultural affinity. Demographic change has already eroded the effectiveness of the GOP coalition, with Democrats winning the popular vote in six of the past seven presidential elections -- something no party had ever previously done.
Trump won the Electoral College in 2016 (while losing the popular vote by nearly 3 million ballots) only by pushing his support among the electorate's most culturally conservative elements -- older, blue-collar, evangelical and rural whites -- to the highest levels seen since Reagan in 1984. Yet that came at the price of a much narrower margin than most Republican nominees have achieved among college-educated white voters -- many of whom are open to arguments for smaller government but were alienated by Trump's personal style and cultural and racial views.
In office, Trump has seen his approval rating fall, relative to his 2016 vote, among both groups. Trump has lost ground among blue-collar whites, especially women, because many came to view the GOP's efforts to repeal the ACA as a threat to their economic security. Among white-collar whites, especially women, the principal problem appears to be his style, rhetoric and demeanor. In a recent ABC/Washington Post poll, fully 70% of college-educated whites said Trump lacked the temperament and personality to serve effectively as president; moreover, two-thirds of college-educated white women said he was biased against women and three-fifths said he was biased against African-Americans. (College-educated white men split about evenly over whether Trump was biased against women, while nearly three-fifths said he wasn't biased against blacks.)
Would tax cuts buy back voters or turn them away?
The great fear among many Democratic strategists has been that with a tax cut, Republicans, in effect, could buy back the loyalty of well-educated whites recoiling from Trump on cultural and personal grounds. But, if anything, polls have shown that white-collar whites are even more skeptical about the tax plan than their blue-collar counterparts.
One recent Quinnipiac University national survey found that while non-college whites split almost evenly on the GOP tax proposals, college-educated whites opposed the plans by more than two to one -- as did the millennial and minority voters more firmly in the Democratic camp. College-educated whites (along with young people and minorities) were also much more likely than blue-collar whites to say that the plan favored the rich "at the expense" of the middle class. Still, despite those relatively more positive responses, just one-fifth of non-college-educated whites said they expected the bill to lower their taxes (not much more than the one-sixth of college-educated whites.)
Looking at these attitudes, Democrats see opportunities in 2018 to pursue blue-collar whites mostly on economic grounds and white-collar ones largely around their cultural distaste for Trump (though the design of the GOP tax blueprint has also provided Democrats an unexpected economic target in suburban districts). In practice, in the Virginia elections earlier this month white-collar whites broke toward the Democrats, while blue-collar and rural whites remained overwhelmingly loyal to the GOP. That pattern suggests the GOP has more to fear from well-off voters who believe the Trump-era party is violating their values than from working-class voters who conclude it is betraying their interests. But as the tumultuous Trump era continues to deconstruct and recombine traditional partisan alignments, neither party can be entirely certain how either group will break in 2018 and beyond.