Democrat Chris Bell, the former Houston congressman and gubernatorial nominee, is formally announcing his U.S. Senate campaign.

Bell, who has been campaigning since early summer, is set to rev up his bid Wednesday with a video in which he calls the Republican incumbent, John Cornyn, a "water boy" for President Donald Trump and offers a sharpened pitch for why he is the best choice in the crowded primary.

"As the only candidate who’s been to Congress, I know how badly broken it is," Bell says. "I’ve fought the same political insiders that keep John Cornyn in power, and I know how to take them down."

Bell, also a former Houston City Council member, served one term in Congress in the early 2000s before falling prey to redistricting under then-U.S. House Majority Leader Tom DeLay, R-Sugar Land. As a freshman, Bell broke a seven-year truce among House members and filed an ethics complaint against DeLay that triggered a series of events leading to Delay's downfall.

Bell's announcement is not a surprise. In early July, he set up a campaign with the Federal Election Commission and said he planned to run but would announce at a later date.

Bell is part of a primary that has grown to nine candidates. They include Houston City Councilwoman Amanda Edwards, Latina organizer Cristina Tzintzún Ramirez, 2018 U.S. House candidate MJ Hegar, Dallas state Sen. Royce West and Sema Hernandez, who got a stronger-than-expected 24% against Beto O'Rourke in the 2018 U.S. Senate primary.

A University of Texas/Texas Tribune Poll released last week found the primary wide open, with no candidate well known statewide and everyone including Bell in single digits after Hegar, who led with 11%. More than half of respondents said they have not yet thought about the race enough to have an opinion.

Bell said he does not "think there's any question" that the nomination is up for grabs and that he was glad he waited to ramp up his campaign until now, "when a lot of people are going to start tuning in and paying attention, and we're perfectly positioned to move forward."

Bell said gun violence has been one of the most striking issues he has heard about from voters since he began stumping. He is one of the more progressive candidates in the primary on the issue, saying he supports an assault weapons ban and buyback program in which people would face civil penalties if they do not turn in their guns for compensation after a certain time period.

For the campaign, Bell has brought onboard veteran Democratic strategist Dane Strother, who got to know Bell during Richard Fisher's 1994 campaign for U.S. Senate in Texas. Strother more recently was media consultant for Tony Evers' 2018 defeat of Wisconsin Gov. Scott Walker.

In an interview, Strother said Bell would distinguish himself with his record of "standing up to power" and an emphasis on ethics, adding that the latter would especially resonate amid the regular scandals coming out of the Trump administration.

"There are quite a few candidates in this race, and if the vote is split many directions and a primary voter is concerned about fixing Washington and about restoring ethics, then I think the more the merrier for Chris," Strother said. "He’s somewhat unique here."

Bell's announcement comes toward the end of the third fundraising quarter, which should provide some new insight into the viability of the candidates, most of whom began their campaigns over the past three months. Bell is scheduled to hold a kickoff fundraiser Wednesday evening in Houston hosted by Bess and Matt Wareing.