Democrat Mike Johnston plans to report his campaign for Colorado’s U.S. Senate seat brought in $1.6 million through the end of the second quarter, cementing a solid fundraising lead among the 10 Democrats hoping to unseat Republican Cory Gardner.

The former two-term state senator from Denver has raised a total of $3.4 million since launching his campaign in January, with donations from residents of each of Colorado’s 64 counties, his campaign said Monday.

While at least one other Democrat running in the 2020 primary has cracked seven figures in contributions – former diplomat Dan Baer said Monday he plans to report $1.35 million in receipts since he got in the race – none of Johnston’s primary rivals are expected to report raising anything approaching his total.

Gardner, who is seeking a second term, raised $2 million through March and reported $3.4 million cash on hand at the end of the first quarter, but by late Monday hadn’t released his second-quarter fundraising numbers.

“It’s clear people across Colorado are fed up with Cory Gardner’s failed leadership in Washington and excited to unseat him and elect a senator that fights for them,” Johnston said in a statement announcing his totals.

“While Cory Gardner has voted with Trump 99% of the time and created new problems on everything from immigration to taxes to health care, I’ve spent my life running at the hardest problems and am ready to do that in the U.S. Senate,” he said. “My campaign is about the people of Colorado, and I’m honored for the grassroots support we have built since the beginning of this campaign.”

Johnston set multiple fundraising records in his run for governor last year before finishing third in the primary, behind then-U.S. Rep. Jared Polis and former State Treasurer Cary Kennedy. In November, Polis defeated Republican gubernatorial nominee Walker Stapleton by a wide margin.

As of when this story was posted at 5:30 p.m. MT Monday, Johnston and Baer were the only Colorado Senate candidates who had released their fundraising totals for the second quarter, which ended June 30. Quarterly campaign finance reports are due to the Federal Election Commission by July 15.

Democratic primary contenders with fundraising track records include former state House Speaker Andrew Romanoff, former U.S. Attorney for Colorado John Walsh, former state House Majority Leader Alice Madden and former congressional candidate Stephany Spaulding.

First-time candidates in the race include scientist Trish Zornio, community organizer Lorena Garcia, climate activist Diana Bray and economist Ellen Burnes.