WASHINGTON — When Plano Rep. Sam Johnson announced last January that he would not seek re-election to the U.S. House, a candidate with a familiar name emerged: Sam Johnson, a 35-year-old Democrat from Plano.

It's not a joke, and it's not part of a plan, the new Johnson promised. After all, he can't help the name he was given, and he's just one of about 3,500 people in the U.S. with the name Sam Johnson, according to HowManyOfMe.com.

“It’s a crazy coincidence, and I totally get that,” he said. “I’ve had the name obviously forever.”

Democratic candidate Sam Johnson is running for the seat of retiring Rep. Sam Johnson. (via Facebook)

Johnson grew up in Plano and started his family in District 3, which is solidly red: The 87-year-old Republican Sam Johnson has held the seat since 1991. In the 2016 election, the congressman easily defeated his Democratic opponent with 61 percent of the vote.

The most prominent Republican on the ticket this year is state Sen. Van Taylor, who has been in the Legislature since 2010. Taylor will face Alex Donkervoet and David Niederkorn in the GOP primary.

But Johnson is optimistic that this year could be different, with no Republican incumbent. Democrats are also hoping for a backlash against President Donald Trump and have been encouraged by recent races in Virginia and Alabama.

Now, Johnson is focused on setting himself apart from the retiring Republican with the same name before the March 6 primary elections.

“If anything, it might make my primary harder because a lot of Democrats do have a bad taste in their mouth with the name,” Johnson said.

Johnson notified the Collin County Democratic Party that he was running for the seat after two candidates had already entered their names, chairman Mike Rawlins said. The party did not recruit him, and it does not endorse primary candidates.

He’s up against three other Democrats — Adam Bell, who ran against the congressman in 2016, Lorie Burch and Medrick Yhap.

Matthew Wilson, an associate professor of political science at Southern Methodist University, said the name could actually help Johnson in the March election among low-information voters.

“Having the same name as the incumbent member of Congress may give Sam Johnson a boost against any rivals in the Democratic party,” Wilson said. “You can assume a certain threshold support just from having the familiar name.”

But it probably won’t be enough to help Johnson in the general election, Wilson predicts. Texas is one of nine states that have straight-ticket voting, and that could mean that Republican voters won’t even look at the race. Instead, they’ll cast a vote for their party. The Texas Legislature ended straight-ticket voting in 2017, but the law does not go into effect until 2020.

Rawlins agreed that straight-ticket voting would keep the name similarity from having much impact in the general election, but it could influence some votes.

“For the die-hard Republican voter, they may be a little bit confused between Sam Johnson showing up this time with a ‘D’ next to his name rather than an ‘R,’” Rawlins said.

Johnson is a lawyer at his own firm — Rosenberg Johnson and Sparks — which has offices in Dallas and Plano. He said he’s always planned to run for office, but moved up his timeline when Trump was elected.

He said he wants to move away from the focus on his name and is hopeful this could be the year Collin County turns blue.

“I think we’ve got a lot of factors in our favor,” Johnson said. “We’ve got that it’s an open seat not held by an incumbent. … And also you’ve got a lot of traditional conservatives who don’t feel like the GOP represents their views anymore.”

But it could just be about the name for some voters, Wilson said.

“Let’s face it: Voters in a very long-shot district for Democrats may just like the novelty value of ‘Hey, we can run Sam Johnson,'" Wilson said. “I would not discount that as one factor some voters may have on their minds.”