Should major parties screen candidates in primary elections?
Marjorie Taylor Greene is a follower of the QAnon conspiracy theory, which states that there is a cabal in the "deep state" and the Democratic Party made up of Satan-worshiping pedophiles. This is a wacko theory with no evidence to back it up, and grew out of the ridiculous "Pizzagate" smear campaign. Greene herself is a wacko and an embarrassment to the Republican Party.
The news media is clutching their pearls over Greene, especially when someone recently dug up that she "liked" content on Facebook that called for the murder of Democrats like Nancy Pelosi. Which leads to this question: What responsibility does the Republican Party have to keep wackos and extremists from becoming nominees? When should party leadership step in and try to stop them?
First, this needs to be said: I do not trust the news media or the Democrats to make that call. Democrats have nominated rabid anti-Semites like Ilhan Omar, and could not bring themselves to denounce Omar's hateful smears of Jews. Democrats need to clean up their own house before trying to "help" the Republicans.
In a perfect world, yes, the Republican party establishment should try to screen out truly fringe candidates. In a crowded primary where a fringe candidate is likely to win with a plurality, it would be wise to encourage others in the field to drop out and endorse the fringe candidate's main rival. If none of the alternatives stand a chance of winning a "first past the post" contest, at least one of them can win. Directly opposing fringe candidates in primaries would also be advisable.
However, there is a serious risk for the Republican Party here. There is a significant amount of resentment toward the establishment, so trying to squeeze out a fringe candidate might actually rally voters to support him or her. If a segment of the base feels disrespected by the party, that will only encourage more support for insurgent candidates. In some cases, doing nothing hurts the insurgent more than openly opposing him or her. Obviously, this also applies to Democrats and their own fringe candidates.
Of course, if the Republican Party establishment - state party leaders, elected officials, and so forth - start trying to squeeze out legitimately fringe candidates, it is likely that the definition of "fringe" will expand over time as the establishment tries to slam the Overton Window shut. conservative voters will not tolerate that, so the party must be very careful not to separate themselves from their own voters.
For the good of the Republican Party and (more importantly) for the good of the country, weeding out radicals is the right thing to do. However, that effort is filled with danger. The party establishment should be aware of the dangers of this strategery, and Republican voters should watch closely and use their primary votes to make sure this is not simply an excuse to prop up the "good old boys club."