Of course, "stupid" is subjective. But by most standards, Republicans fit the bill. In September, Public Policy Polling found that "66% of [Donald] Trump's supporters believe that Obama is a Muslim... 61% think Obama was not born in the United States." The same poll found that 54 percent of all Republicans believed the President to be a Muslim. (In September Donald Trump suggested Obama is a Muslim.)
In 2013, Louisiana Republican Governor Bobby Jindal warned the GOP to "stop being the stupid party." Jindal said Republican candidates should "stop insulting the intelligence of voters... with offensive and bizarre statements." However, Jindal didn't listen to his own advice; on May 10th, Jindal endorsed Donald Trump. Stupid is as stupid does.
It wasn't always like this. Fifty years ago, Republicans seemed wrongheaded but intelligent. What has happened to the Grand Old Party? Its transition to the stupid party had four stages:
1. Republicans adopted an anti-intellectual strategy. Political historians have noted the long-term political consequences of Richard Nixon's southern strategy which peeled Southern white voters -- particularly evangelical Christians -- away from the Democratic Party. What hasn't received as much attention is the fact that southern evangelicals are not intellectual: they believe in the literal true of the Bible; for that reason, they believe the universe was created in seven days and decry evolution and science. Writing in The Weekly Standard, Henry Olsen observed the GOP southern strategy caused the "dumbing down of conservatism." "Evangelicals have long shied away from engagement with the less-devout world... as a group they tend to lack intellectual curiosity and rigor."
In September, writing in the Daily Beast Ana Marie Cox observed, "Trump and [Ben] Carson are winning a huge slice of the GOP base because of [their] prideful ignorance, which to voters signifies not just a rejection of the establishment or elites but a release from the hard work of having to think."
Now the Republican nominee is Donald Trump, an anti-intellectual. For example, early in May, Trump cited a National Enquirer article linking Ted Cruz's father to the JFK assassination. Trump's policy positions are incoherent and GOP voters don't care.
2. Republicans accepted racism. When the GOP adopted the southern strategy, they tacitly accepted racism. With Trump this racism has come out in the open.
Writing in Psychology Today, David Niose linked anti-intellectualism and racism:
Critically thinking individuals recognize racism as wrong and undesirable, even if they aren't yet able to eliminate every morsel of bias from their own psyches or from social institutions. An anti-intellectual society, however, will have large swaths of people who are motivated by fear, susceptible to tribalism and simplistic explanations, incapable of emotional maturity, and prone to violent solutions.
Ana Marie Cox commented on the state of today's Republican Party: "You can't spend 40 years tacitly making racists feel welcome in your party and expect the intellectual atmosphere not to suffer, or for that anti-intellectualism to stay bounded with race."
In 2015, Donald Trump brought racism out of the GOP closet. He damned "political correctness" and brought his hate-filled bigotry into mainstream political discourse.
3.Republicans enabled hate. Writing in Mother Jones, David Corn observed that starting with Sarah Palin in the 2008 presidential campaign, GOP politicians and their cohorts in the conservative media launched a campaign of hatred towards President Obama (and scorched-earth obstructionism of his agenda): "It's been a long run of Republicans accepting, encouraging, and exploiting uncivil discourse, anti-Obama hatred, and right-wing anger."
The New York Times observed that Donald Trump feeds into this hatred by encouraging violence at his rallies.
Writing in The Weekly Standard, Henry Olsen observed that over the past two decades Republicans have created "an alternative conservative media universe... [that] led to a conservative ghetto where well-meaning conservatives can live without ever coming into contact with people who disagree with them."
Since 1874 an elephant has been the Republican symbol. A better symbol for the current Republican Party would be the mushroom: voters who are kept in the dark and fed bullshit.
4. The Republican rank-and-file separated from the Washington elite and embraced anarchy. The candidacy of Donald Trump is a logical outcome of the Tea-Party movement that first decried the Washington establishment and then bemoaned the failure of Republican congressional leadership to keep promises made during the 2012 and 2014 elections (abolish Obamacare; reduce the size of government; etc.).
The GOP rank-and-file embraced Trump because he is an outsider -- someone with no government experience -- who embraces the core Republican values: anti-intellectualism, racism, nativism, and sexism. They love Trump because he is opposed to political correctness and tells them it is okay to be white.
First came the stupid party. And then came Donald Trump.