Excerpted from political consultant and pollster Stanley B. Greenberg’s new book, America Ascendant: A Revolutionary Nation’s Path to Addressing Its Deepest Problems.

When your jaw drops watching every step in the battle for the heart of the Republican Party and the selection of their national leader, you should always keep in mind who now identifies with this party. It is a lot fewer voters than it used to be and their popularity has fallen to Watergate levels on many measures.

The evangelicals and the Tea Party are the heart of the Republican Party. About seven in ten strongly identify with the Republican Party, and they are the base segments most likely to vote straight Republican on Election Day. They do not look like the new American majority. The evangelical, observant Catholic, and Tea Party base voters are nearly 90 percent white, and two-thirds are married—in stark contrast to a country that is growing more racially diverse and increasingly single.

There is a “moderate” bloc among Republicans — voters who are ideologically or religiously moderate — who are pretty alienated from what they see as the mainstream of the party. They form 25 percent of the GOP base. The moderates are buttressed by the 5 percent of Republican base voters whom I label the “GOP establishment.” They would probably rally to a candidate backed by the party’s established leaders.

This is a party where Evangelicals, observant Catholics, and the Tea Party are rallying the troops into battle and they are pushing Donald Trump, Ben Carson, and Ted Cruz to the top.

When asked about the direction of the country, their starting reactions were “worried,” “discouraged,” “scared,” and “concerned.” While many voters and even some Democrats doubt that Obama is succeeding and accomplishing his agenda, Republicans think he has won. To them, Obama imposed his agenda, and Republicans in Washington let him get away with it. The country is sure that gridlock has won the day, but Republicans see a president who has lied, fooled, and manipulated the public to pass a secret socialist agenda.

The Republican base thinks they face a victorious Democratic Party that is intent on expanding government to increase dependence and therefore electoral support. It starts with food stamps and unemployment benefits, and expands further if you legalize illegal immigrants; insuring the uninsured through the Affordable Care Act will dramatically expand the number of those dependent on the government. They believe these policies are part of an electoral strategy — not just a political ideology or an economic philosophy. If Obamacare is fully implemented, they fear the Republican Party may be lost forever.

While few explicitly talk about Obama in racial terms, the base supporters are very conscious of being white in a country with a growing minority population. Their party is losing to a Democratic Party whose goal is to expand government programs that mainly benefit minorities. Race remains very much alive in the politics of the Republican Party.

For all that, this is a deeply divided base. Moderates are a quarter of those who identify as Republicans, and they are very conscious of their discomfort with other parts of the party base. The moderates are fiscal conservatives who feel isolated in the party. Their distance begins with social issues such as gay marriage, abortion, and whether homosexuality should be discouraged by society, but it is also evident on issues such as climate change, undocumented immigrants, and the Second Amendment.

The moderates are increasingly marginalized in their party as the other segments grow more defensive of views that are increasingly unpopular and under threat nationally. Evangelicals feel most threatened by the ascendant demographic and cultural trends in America and bring unique intensity to their opposition to what is happening with homosexuals.

Abortion is one of the issues where evangelicals and the Tea Party base are equally aligned and intense — and they have led the charge in that battle against the trends in marriage and independence for women. The observant Catholic bloc is strongly opposed to the growing public acceptance of homosexuality and gay marriage though less intense than the evangelicals on this issue.

What has become apparent is how intent the Republican base voters are to battle against the current trends led by the national Democrats, how high the stakes are for them, and how deeply their emotions run.

That is what fueling the Republican primaries and determining who will lead the Republican Party at this critical time.

Excerpted from A Revolutionary Nation’s Path to Addressing Its Deepest Problems by Stanley B. Grenberg, published on November 3, 2015 by Thomas Dunne Books. Copyright © 2015 by Stanley B. Greenberg. All rights reserved.

If you enjoyed this excerpt, purchase the full book here.