A politician has a choice to make when he or she is running for office: One can hold a position that comports with one's beliefs even if the electorate objects, or one can tell the electorate what it wants to hear.

In the overlap of climate change politics and the 2016 election, Republican candidates are almost uniformly rejecting the idea that human activity is making the world warmer. (Jeb Bush has offered that he's "concerned" about warming, for what it's worth.) In most cases, that's because they don't accept the scientific link between the two. But even if they did, the electorate doesn't want to hear it.

On Wednesday -- it's Earth Day, we'll note -- Gallup pointed out that the most skeptical political group on the subject is conservative Republicans. Just more than one-third of that group thinks it will see the effects of climate change in its lifetimes, and 40 percent think it will never happen.

In part, that's because the Republicans furthest to the right are also most likely to reject the scientific consensus that human activity is to blame.

Why does this matter for 2016? Because conservative voters turn out heavily in primaries.

In 2012, two-thirds of the Republican primary electorate identified itself as conservative or very conservative in exit polling. Only one-third identified itself as being moderate or liberal Republicans. When two-thirds of voters overlaps with the group that's most likely to reject the idea that we should address climate change, that's a strong disincentive to hold your ground on the subject.

And we see that in polling. In February, NBC News and Marist College surveyed primary voters in Iowa, South Carolina and New Hampshire. Republican voters in Iowa and South Carolina said that the position they would find most unacceptable from a presidential candidate was "believ[ing] that climate change is man-made and action should be taken to combat it." Fifty-six percent in Iowa said it was either "mostly" or "totally" unacceptable. In South Carolina, it was 54 percent.

Perhaps more interestingly, just 9 percent of likely Iowa GOP caucus-goers and 16 percent of likely South Carolina primary voters find such a position "totally acceptable." In other words, there's very little reward for Republicans to go out on a limb on this and push for action.

It's fair to wonder how the chicken and egg relate on this. Republican politicians have spoken out against action on climate change for some time now, and the Republican electorate agrees. When Yale University earlier this year released maps of people's attitudes toward climate change, we noted that the view held in any congressional district served as a good predictor of how that district voted in 2012. The more likely the district to accept the science, the more likely it backed President Obama, and vice versa.

For a Republican who wants to win the party's presidential nomination, then, holding a strong, public position on climate change is a risk. See Newt Gingrich in 2012, who furiously back-pedaled from his once having appeared in an ad with Nancy Pelosi calling for action on climate change.

That's not what voters want to hear. And political candidates in a polarized country are all too often in the business of saying what voters want to hear, not necessarily what they actually believe.