My brother thinks Dems/Libs are a minority that want to rule the country. I would've asked him to explain except at that point the object is to get him to not explode - once he explodes it's off into a rant that usually has little to do with the conversation.

There are many ways to evaluate this. You could, for example, add up the populations of red state vs blue states and see which Governors have more votes in total. Or maybe do the same for Mayors in every cit in the country.

The easiest way, I guess, is simply to look at the vote totals in the Presidential elections every four years, as those give a pretty clear picture of whether more people are voting Republican or Democratic. (For those who say “Well, those votes are probably rigged” the answer is: Both parties have enjoyed full control of government at one time or another over the past 40 years, including as recently as Trump in 2016 and Obama in 2008 elections, so presumably they have had a chance to fix it, assuming it’s actually a problem (which ever analysis has shown it’s not. But I digress.)

1992 Election: more Democratic votes than Republican. Clinton elected.
1996 Election: more Democratic votes than Republican. Clinton re-elected.
2000 Election: more Democratic votes than Republican. Bush elected via Electoral College, not popular vote.
2004 Election: more Republican votes than Democratic: Bush re-elected.
2008 Election: more Democratic votes than Republican: Obama elected
2012 Election: more Democratic votes than Republican: Obama re-elected
2016 Election: more Democratic votes than Republican: Trump elected via Electoral College, not popular vote
2020 Election: more Democratic votes than Republican: Biden elected.

To be clear: Democrats have gotten more Presidential votes in every election but one since 1992. Minority? Not hardly