Multiple Republican operatives familiar with Texas polling data are convinced GOP Rep. Pete Sessions (TX-32) is, at the moment, the most vulnerable incumbent in the Lone Star State. The powerful House Rules Committee chair's rapidly moderating Dallas district voted for Hillary Clinton 48 percent to 47 percent in 2016. And despite serving as NRCC chair in 2010 and 2012, Sessions hasn't had to run a competitive race since 2004.

Moreover, Democrats' nominee offers a stark contrast to Sessions. In late May, civil rights attorney Colin Allred won the Democratic runoff with 70 percent of the vote. Allred was a star linebacker at Dallas's Hillcrest High School and went on to play for Baylor University and four seasons on special teams for the Tennessee Titans. Allred, a 35 year old African-American, is 28 years younger than the 11-term incumbent.

Allred raised $1 million for the primary phase and will highlight his life story, including being raised by a poor single mother who taught in Dallas public schools (by contrast, Sessions is the son of a former FBI director), playing in the NFL and earning his law degree from the University of California, Berkeley. Democrats view Allred's profile as symbolic of this highly professional, suburban district that is almost 50 percent non-white.

Sessions had $1.5 million on hand at the end of March and as a former NRCC chair, he won't lack for money. His backers insist that even though he didn't have a Democratic opponent in 2016, he's prepared for a rigorous race this November.

At the NRCC, Sessions earned a reputation as a take-no-prisoners aggressor, but his team will work to soften his image as a hardline, pro-Trump partisan. Sessions will point to the tax cut bill as a boost for Dallas's high-tech corporate sector and will remind voters he procured funding to secure the failing Lake Lewisville Dam. He'll also highlight his outreach to the local Hispanic and Asian business communities.

Allred talks about helping small businesses and doesn't come across as a Sanders/Warren-style agitator. But Republicans will try to define him as a Berkeley-indoctrinated liberal who supports single-payer healthcare and gutting the tax cuts. They'll also note he's a close ally of failed 2014 gubernatorial nominee Wendy Davis and worked in the Obama administration (he was briefly an assistant counsel under HUD Secretary Julian Castro).

The biggest challenge for Sessions may be rebuilding his own political brand after over a decade without a real race. Since Sessions defeated Democratic Rep. Martin Frost in a multi-million dollar 2004 affair, thousands of professional workers have moved from blue states to the northern Dallas suburbs and brought their political values with them. And suddenly, their only way to send a message to President Trump is on the congressional ballot.

Both parties are likely to invest millions in the expensive Dallas media market to win this seat. It moves from Lean Republican to the Toss Up column.