There's a reason why Donald Trump is stirring up the Republican race. The Republican Party has become a resistance movement, and Trump is leading the resistance.
What it's resisting is the rise of the New America. That's the coalition of groups that were historically marginalized: immigrants, racial and religious minorities, gays, working women, single mothers, young people and "unchurched" Americans with no religious affiliation.
It's a coalition united by a commitment to diversity and inclusion. And deeply opposed to symbols of exclusion like the Confederate flag, hostility to immigrants and homophobia. The coalition is growing in numbers as the U.S. becomes more racially diverse, women become more independent, gays come out of the closet and more people lose their religion.
The New America came to power with the nation's first African-American President. President Obama's legitimacy is under constant challenge -- most prominently by Donald Trump, who has never given up disputing Obama's legal qualifications to serve.
Republican leaders know that conservative hostility to immigrants and minorities will doom their party. It's the same mistake Republicans made 100 years ago when they were unwelcoming to immigrants from southern and eastern Europe. Those immigrants and their children became the base of the New Deal Democratic majority that dominated American politics from the 1930s to the 1970s.
Then, as now, Republicans staunchly defended the Old America, which sees itself as under assault.
The Hollywood celebrity speaker at the last Republican National Convention was the very symbol of the Old America -- Clint Eastwood, age 82.
The Democrats' celebrity speaker was Scarlett Johansson, age 27.
The Republican Party chairman has urged Trump to "tone it down" to avoid damaging the party brand. Instead, Trump has been racheting it up. "We have to take back the heart of our country," Trump told a rally in Phoenix last weekend, to which the audience responded with cheers of "USA! USA!"
The latest Economist-YouGov poll puts Trump at the head of the GOP pack for the 2016 nomination. Trump's favorability among Republicans jumped from 38 percent in June to 49 percent this month. His highest ratings come from the the party's base: "very conservative" Republicans, Tea Party supporters and Republicans over 65. Literally, the Old America.
Trump evokes conservatives' longing for an America that dominates the world with its wealth and power. "We don't have victories any more. We used to have victories," he told the crowd in Arizona. "We need somebody that can take the brand of the United States and make it great again."
Trump divides the world into winners and losers. He says he can make the U.S. a winner. Why? Because he's a winner. "I'm really rich," he boasted. Which, by his calculation, makes him smarter than everybody else. He claimed, "We need a leader that wrote The Art of the Deal."
Who would be better at dealing with Iran than the consummate deal-maker? Trump pledged, "We won't be using a man like Secretary Kerry who has no concept of negotiation, who's making a horrible and laughable deal."
Trump's claims are completely ridiculous, but they have tremendous appeal to conservatives who see their America disappearing. What unites Republicans today is the call for resistance. Resist Obamacare. Resist immigration reform. Resist same-sex marriage. Resist Islamic radicalism. Put up a wall of resistance to anything President Obama wants to get out of Congress.
Is Trump a serious threat? Only 18 percent of Americans have a "very favorable" opinion of Donald Trump. Forty-six percent are "very unfavorable." The base of Trump's support is the limit of his support. He can get support from staunch conservatives who rally to his call for resistance. But he can't get support from anybody else.