Is Trump Rreally a Threat to the Repubcan Party?

To hear GOPe tell the story, Trump is going to be massively defeated by Clinton.  Yet this report makes me ask Are all these Republican primary voters really Democrats?  Or is Trump mobilizing what used to be Reagan Democrats?  People who want jobs again?  4/25/16 Breitbart:

Newly compiled data after the New York Republican primary shows that among the states that have voted so far in 2016, GOP primary and caucus turnout is up well more than 8 million votes and well more than 60 percent over 2012’s process.

Top GOP officials say that the intense interest in the GOP primary throughout the year so far only serves to benefit the Republican nominee in November, whoever it ends up being.

In total, so far, nationwide the GOP has seen an increase of 8,719,041 votes in 2016’s primaries, caucuses and conventions over 2012’s primaries, caucuses and conventions. In 2012, 14,452,500 people voted in each of the states and territories that have held contests so far in 2016. In 2016, 23,171,541 people have voted in the GOP contests so far. That is a 60.33 percent increase in GOP contest turnout in just four years.

My experience and traditional political science says Republicans are consistent voters (unlike Democrats) and they turn out even in uncontested primaries.  This growth is likely Americans who finally have realized the Democrats are the billionaire's party.