(CNN) There has been a belief among some Democrats that the combination of non-white voters being overwhelmingly Democratic and the fact that they are becoming a larger portion of the electorate means that Democrats may be heading toward some sort of electoral glory.

This increase in diversity is a comfort to some opposed to President Donald Trump who believe that better times are around the corner.

Nowhere is this idea more challenged than in Nevada. Republican Sen. Dean Heller from Nevada is one of the most endangered incumbents this cycle.

The fact that Heller is even competitive, though, in Nevada is a major blow to the idea that the Republican Party is bound to be in trouble because of the shifting demographics in this country.

The only poll that used live interviews and called cell phones of the race (conducted for the Nevada Independent ), has Heller up 40% to 39% over probable Democratic nominee Jacky Rosen. With Trump's low standing in Nevada and nationally, Heller still faces an uphill climb, but he's still in the race.

So what has happened in Nevada that has allowed Republicans to stay competitive?

It's actually fairly simple: the white population become much more Republican leaning. Although exit polls are from perfect, they illustrate this phenomenon quite well. In 1992, Bill Clinton defeated Republican George H.W. Bush by 1 point among white voters. This past presidential election Trump won among them by 18 percentage points. The same trend of whites moving towards the Republican Party has exhibited itself nationally.

Nevada's electoral landscape argues very much against the idea that Democrats should take much if any comfort in America's changing demographics. It's a state that has become incredibly more diverse in the past 25 years or so.

The incredible climb of the minority population in Nevada was on full display in 2016. There were images of Latino voters standing on a long line in order to cast votes in early voting. Some analysts thought it was a sign that Trump was headed towards defeat. He, of course, won nationally. And while Trump did lose Nevada, it was an incredibly close race.

Indeed, the presidential result in 1992 and 2016 elections in the state were essentially the same, even as the state became more diverse. Democrat Bill Clinton won by 3 percentage points in 1992. Democrat Hillary Clinton won by 2 percentage points in 2016. (The national environment was also fairly similar in both years with Democrats winning small victories in the national popular vote.) It should be noted that independent Ross Perot received a significant share of the vote in 1992, but exit polls reveal Clinton still would have won the state without him running.

You can also see the lack of movement toward the Democrats in Nevada by examining the party registration statistics. Before the 1992 election , Democrats held a 6-point advantage in party registration. Before the 2016 election , the Democrats held a 7-point advantage in party registration.

Today, there's no indication that the state is becoming any more Democratic. Trump's approval rating in Nevada was actually 4 points higher than it was nationally over the course of 2017, according to Gallup. The Democratic lead is back down to a 6 points in party registration

There's no reason to believe that this significant shift towards the Republican Party among white voters can't continue. Look at what happened in Texas: an even more diverse state with a growing Latino population. In the 1992 exit polls , whites made up 74% of voters and went for Bush by 21 percentage points. That allowed Bush to carry the state by 3 percentage points . This past presidential election Trump won the state by 9 percentage points, even as whites made up 57% of voters in the exit polls. Trump expanded upon Bush's margin because he won white voters by 43 percentage points (or more than double Bush's margin).

Nationally, Republicans have a lot more leeway to play with in future elections. Whites still make up 70% or greater of voters nationally (depending on what measure you use), even as the country is growing more diverse. If there is a candidate or party who makes an outright appeal to them, whites may react by giving them their votes. That could be enough to win, as Trump's election indicates.

In Nevada, the shift among white voters towards the Republican Party gives Heller some chance at reelection. Now, he has a better shot of losing than winning, but the fact that he has any shot at all should demonstrate to Democrats that more non-white voters entering the electorate is no guarantee of a massive shift in their chance of victory.