At this moment, political leaders and strategists in both the North Carolina Democratic and Republican parties are concocting the same kind of fantasy — that they’ll be able to wall off their state and local candidates from a potential disaster at the top of the ticket.

While I think these politicos are mistaken, I don’t really blame them for their fantasizing. Imagine that you are a Democratic strategist in North Carolina. You’re watching Hillary Clinton’s deteriorating poll numbers. You’re also thinking that neither Joe Biden nor Bernie Sanders would be an adequate substitute as an energetic, appealing head of the Democratic ticket in 2016. Wouldn’t you be trying to figure out how to run Roy Cooper for governor and pick up some legislative and county commission seats anyway, despite the expected headwind?

Now imagine that you are a Republican strategist. You’re watching Clinton’s sinking fortunes as well, but you’re also looking at polls showing Donald Trump and Ben Carson leading the field both nationally and in the early-primary states. You worry that neither has the background or temperament to capitalize on the Democrats’ weakness. You further worry that Trump, in particular, could self-destruct in a way that would deeply wound the GOP as a whole. Wouldn’t you be trying to figure out how to get Gov. Pat McCrory reelected and protect Republican seats in such a scenario?

Of course. I would, too. The problem is that, contrary to popular belief, there are fewer ticket-splitters and truly independent voters today than there were in the past. Don’t pay attention to party registration. That ceased being a useful metric some time ago. Plenty of people without a formal party affiliation are, in practice, loyal Democratic or Republican voters.

Even in the 1990s and early 2000s, there were many members of Congress whose party affiliations differed from how their districts voted in presidential or other statewide elections. Now there are few. The phenomenon is even more pronounced when you proceed down the ballot to state legislative seats. The decline of split-ticket voting is a trend that political scientists have confirmed with hard data and attributed to a variety of factors that have polarized the electorate into more ideological coherent, mutually antagonistic camps.

One implication is that in a presidential election year, how each party’s base feels about the top of the ticket will probably a huge effect on all the other races. If Democrats are enthusiastic about their nominee in 2016, it won’t take much effort to get them to vote for Roy Cooper and other Democrats (if they mark their ballots all the way down, that is). The same goes for the Republicans.

There’s nothing new about turnout effects, of course. GOP fortunes in North Carolina surged with Richard Nixon’s easy reelection in 1972 and Ronald Reagan’s landslide reelection in 1984. The difference is, however, that there aren’t as many split-ticket voters for campaigns to reach out to as a way of counterbalancing the presidential effect, as Gov. Mike Easley did as recently as 2004 when he won reelection with 56 percent of the vote while President George W. Bush was winning 56 percent of the vote in his reelection bid.

To say there are fewer split-ticket voters than there used to be is not to deny their existence altogether. When presidential contests are very close, as they were in North Carolina in 2008 and 2012, you can still see their effects. I guess that’s not what I see coming in 2016, however. I think there will be a clear break in one direction or the other.

If Hillary Clinton survives her current woes without criminal indictment and regains her footing in a race against a weak or unsalable Republican nominee, North Carolina Democrats will be gleeful and McCrory will try desperately to separate himself from the national ticket. On the other hand, if GOP primary voters choose wisely, I suspect it will be Cooper running away from his party’s standard-bearer much as Easley kept his distance from John Kerry.

It worked in 2004. I don’t think it will work in 2016.

John Hood is chairman of the John Locke Foundation. Follow him @JohnHoodNC.