Like @keobooks, I disagree with that conspiracy theory because of the support Trump has garnered. If it were a conspiracy then it backfired spectacularly.
When a racist with multiple divorces and multiple bankruptcies is a sign of tolerance, marital sanctity and fiscal responsibility to the Conservative base and they truly want him to lead our nation, that tells you more about what sort of people support the Republican party than anything else. If that were not what most Conservative voters wanted, Trump’s numbers would be far lower as they rallied around less extremist candidates.
The only way of getting those sort of numbers is if it’s actually what voters want. Trump’s popularity is embarrassing to the Republicans as it is concrete evidence of what sort of people the Republican base has. In doing so, Trump ruins the chances of any other Republican candidate getting votes from the swing voters unless they alienate their base, pretty much ensuring a Republican loss in the 2016 election.
A more valid argument could be made about the Sanders candidacy being a Republican conspiracy to split the Democrat’s base and win 2016 by “divide and conquer”. Sanders is no more extreme than the average European and thus able to appeal to swing voters without totally alienating the base. If Bernie’s presidential bid were a conspiracy, then it would be a successful one due to being subtle enough to avoid suspicion while also being quite effective.
Then again, I’m not sure how many Republicans know what a real conspiracy is and just like using that buzzword. Jade Helm, anyone?