DENVER – Coloradans will be feeling the outreach of the Voter Participation Center, urging them to register to vote, as the Washington, D.C, nonprofit aims to fire up and sign up millennials, people of color and unmarried women.

The organization brands the demographics the “Rising American Electorate.” Those broad Democratic-leaning blocs net 53.5 percent of Colorado’s eligible voters. But only about half of them are registered to vote, according to census data gleaned by the organization.

VPC is mailing 120,000 registration forms to hit Colorado homes Wednesday through Saturday.

“Nearly 1 million people of color, unmarried women and millennials aren’t registered in Colorado, which means they aren’t able to have their voices heard in our democracy,” Page Gardner, the founder and president of the Voter Participation Center, said in a statement.

With its majority of voters, the Rising American Electorate “should be reflective of their strength in the population,” Gardner urged.

They’re not an empty-pockets ally to the left, either. Last year the group spent a reported $1 million to turn out “underrepresented” voters for legislative and gubernatorial races in Virginia, Politico reported.

Democrats rode a wave in Virginia, picking up 15 seats in the House of Delegates and the governor’s office.

The Voter Participation Center’s researchers, however, are predicting an “enormous” drop-off in midterm voters in Colorado this year from those blocs. The nonprofit estimated that 31.2 percent – 405,000 voters from the three categories – who voted in 2016 won’t do so this year.

That’s twice the rate among those who don’t fall in those demographics, the VPC predicts.

The VPC has been around since 2003. It started out as the Women’s Voices Women Vote campaign. In addition to voter research, the VPC claims to have registered almost 4 million people across the country, including 120,000 Coloradans since 2006.

The organization, however, has generated criticism for its overly broad pitches to register people (and sometimes dead people or pets) or for confusing people who are already registered. The nonprofit relies on commercially available lists that sometimes contain errors. Anyone who receives an errant voter registration card should throw it away, election officials in other states have advised.