During the primary election, Democratic and Republican voters across the Houston region will have the opportunities to cast their ballots for their congressional candidates. Some races have become so heated that they're attracting national attention. In other races, well-heeled incumbents face underfunded challengers and the outcomes seem practically predetermined. In the middle are those primary races in which candidates compete to become their party's nominee for a tough assignment in an unfriendly, gerrymandered district. Nevertheless, Republican and Democrats alike should aspire to put forward their best candidates. Early voting runs from Tuesday, Feb. 20 through Friday March 2. Election Day is March 6.

ENDORSEMENTS: See which candidates have been backed by the Houston Chronicle editorial board

Republicans

United States Representative,District 29: Phillip Aronoff

The seat being vacated by U.S. Rep. Gene Green may not look like fertile territory for the four candidates in this Republican primary - the largely Hispanic 29th Congressional District is one of the most Democratic-leaning in Texas. However, the district's low turnout creates an opportunity for an ambitious Republican to hit the pavement, activate non-voters and win in November.

Based on his knowledge and political experience, Phillip Aronoff would be the best choice.

Aronoff, 72, has spent decades involved in local government, including as executive secretary for the Consular Corps of Houston, on Mayor Annise Parker's International Trade and Development Council and as a member of the Harris County Housing Authority. He is fluent in Spanish and has an extensive record within the Republican Party that spans from George W. Bush's gubernatorial campaign through Jack Kemp's run for the presidency. His work in the import business and international relations would make him a prime representative for a district that includes the Port of Houston and circles north from Pasadena through Jacinto City to cover northside neighborhoods.

Aronoff told the editorial board that he is running to help recruit conservative Hispanic voters and prevent Texas from going the way of "Pete Wilson's California" - referencing the anti-immigration governor whose policies have been cited as a key factor behind the decline of the Republican Party on the West Coast.

We were also impressed by Carmen Maria Montiel, 53, who is originally from Venezuela and has worked for Telemundo. She spoke passionately about her desire to save the United States from the political fortunes that befell her home nation, and about her admiration for President Ronald Reagan - especially his decision to grant amnesty to undocumented immigrants.

Also running are Jaimy Z. Blanco, a rental agent and political activist; and Robert Schafranek, who ran for this position in 2016.

Democrats

United States Representative, District 10: Mike Siegel or Tami Walker

Seven candidates are running for this sprawling rural and suburban district that stretches from Austin to (almost) Houston. We recommend that Democratic voters send representatives from those two urban poles to compete in the almost-inevitable runoff: Austin assistant city attorney Mike Siegel and Katy-area attorney Tami Walker.

Siegel, 40, who graduated from Cornell Law School, said his boss once jokingly described Siegel's job as waking up, suing Gov. Greg Abbott and going home. He is involved in Austin's lawsuit against SB4, which abrogates local law enforcement discretion on immigration issues. Siegel has the passion of a professional politician, and we mean that as a compliment. However, his focus on renewable energy might fit well in Austin, but will likely run into a few bumps in Houston's oil and gas enclaves.

Walker, 53, lives in Katy and after graduating from the University of Texas School of Law spent nearly three decades working as an attorney or general counsel in different industries. Her soft-spoken style embodies the moderate position of the suburban, oil patch Democrat.

Siegel, a former teacher, appears better versed on the legislative process; Walker, who earned an accounting degree, possesses an appealing common-sense approach.

We were also impressed by Madeline K. Eden, a Bastrop-based chief technology officer with a passion for everything cyber, including blockchain technology, net neutrality and election security.

The other candidates are Matt Harris, who has valuable insights about how to address the concentration of wealth in this country through tax policy, and Kevin Nelson, who has a doctorate in philosophy and is unemployed. Tawana Walter-Cadien and Richie DeGrow did not meet with the Houston Chronicle editorial board.

It will be an uphill battle for Democrats in this traditionally Republican district which includes all of Austin, Colorado, Fayette, Waller, and Washington counties, and parts of Bastrop, Harris, Lee, and Travis counties. Walker or Siegel offer the best opportunity for a real campaign against Republican incumbent U.S. Rep. Michael McCaul.

United States Representative, District 22: Sri Preston Kulkarni

Incumbent Republican Congressman Pete Olson has attracted a total of eight challengers on both sides of the partisan divide to represent this diverse, suburban district that covers part of Harris County, most of Brazoria County and Fort Bend Counties, including Sugar Land. In the five-way Democratic primary, Sri Preston Kulkarni stands out as the most impressive candidate. As a foreign service officer in the U.S. State Department, Kulkarni served in Russia, Jerusalem and Iraq. He also worked as a foreign policy advisor to U.S. Sen. Kirsten Gillibrand, D-N.Y. All that international experience doesn't mean Kulkarni, 39, ever lost his Houston roots. Kulkarni was quick to discuss flooding problems in Cinco Ranch when he met with the Houston Chronicle editorial board. He talks like a real Texan when it comes to energy policy, focusing on the reality of how market forces promote natural gas over coal, and how renewables threaten to do the same for our oil and gas economy. Kulkarni also keeps a focus on the district's diversity - nearly a quarter Asian - and is promoting his campaign in Spanish, Chinese, Hindi and Vietnamese.

That's not to say the other candidates weren't impressive in their own right. Letitia Plummer is a dentist who was inspired to run because of her passion for adoptive parents' rights and has had significant success in fundraising; Steve Brown served two terms as chairman of the Fort Bend County Democratic Party and has run previously for state representative and Texas Railroad Commission; Mark Gibson is a retired Army colonel with 30-years service and was the Democratic nominee for this race in 2016. Margarita Ruiz Johnson did not meet with the editorial board.

United States Representative, District 36: Dayna Steele

Back when she had a talk radio show, Dayna Steele had one rule: Never talk about politics, religion or cats. All that changed with the 2016 election. After taking part in the Women's March, the former KLOL disc jockey decided to run to represent the massive 36th Congressional District, which sprawls from Galveston Bay to the Louisiana border, including the Johnson Space Center. Despite the district's size, Steele, 58, has the natural ability to rattle off the specific challenges facing cities and towns that often go ignored in the deep-red district's traditionally non-competitive races. Those challenges includes the job cuts in the lumber industry, the lack of broadband internet access, and the limited health care services.

"There is a hospital in Orange County, they call it the Band-Aid station, because that's about all you can get there," Steele told the editorial board. She says that's why she supports Medicare for All.

Steele also points out that Congress needs to provide oversight on post-Hurricane Harvey recovery funds to ensure they end up in the poor towns that need help the most.

"It never gets down to the people in Winnie and Rose City and Bridge City and Orange and West Orange," she said.

In this friendly primary, Steele is running against her former mayor, Jon Powell, who has a master's degree from Brown University and spent his career in science consulting and management. He served one term as mayor of Taylor Lake Village in the Clear Lake area and is a compelling candidate as well. If Steele embodies the women's movement that arose after the 2016 election, then Powell is a representative of the science-minded activists frustrated with a disdain for facts, lack of expertise in government and threats of budget cuts to NASA and other federal research outlets.

Powell would make for a fine nominee, especially when he talks about federal investment in infrastructure, but he cannot match Steele's genuine charisma - and that will make her the stronger candidate for Democrats come November.

Whoever wins will have to inspire voters from NASA and throughout Newton, Jasper, Tyler, Polk, Orange, Hardin, Liberty, and Chambers Counties in order to defeat incumbent Republican U.S. Rep. Brian Babin.