Alright, lets look at this critically.

Only 58.1% [158 million people] of the American public voted for President in the 2016 election (https://guides.libraries.psu.edu/post-election-2016/voter-turnout).

There are 336 million people in the US. Trump got 48% of that 158 million or 75.84 million, or approximately 22.5% of the support of the entire voting Nation (but the majority of those polled afterward that did not vote showed a clear leaning toward Hillary over trump). Hardly a majority, white or otherwise.

Presently his approval rating is at 41% or approximately 137.75 million adult voters. (see below - taken from URL above)