Democrat Mike Siegel, vanquished in November by U.S. Rep. Michael McCaul, R-Austin, in a close race that caught political observers by surprise, is running again in 2020.

Siegel, an attorney for the city of Austin, lost to McCaul by 4.3 percentage points. The margin was the closest since the district was redrawn in 2003.

The district stretches from Lake Travis to the Houston suburbs and includes Austin neighborhoods Allandale, Rosedale, Crestview, Brentwood, North Loop, St John’s and the Domain.

Siegel said he hopes to improve the lives of Texans by focusing his campaign on health care, voting rights, job growth and criminal justice reform. He also said that Congress needs to exercise its duty in overseeing the president.

"We held a seven-time incumbent with enormous personal wealth to 51 percent of the vote," Siegel told the American-Statesman. "Now, that last couple percent is obviously the hardest percent, and that's why I need to start now."

Until 2018, the seat had been considered a "safe" Republican seat by national political pundits. In 2004, McCaul was elected to his first term with no Democratic challenger.

"The district is proof of concept that these districts are flippable," said Cliff Walker, political director of the Texas Democratic Party.

However, Siegel and other Democratic candidates benefited from the strong campaign of Beto O’Rourke, who lost to U.S. Sen. Ted Cruz, R-Texas, by 2.6 percentage points.

Siegel said he had questioned how he could mount a successful campaign without excitement from the Senate race, though he was encouraged when 125 people came to his kickoff event Sunday.

"To me, that shows that people who were involved in that work for change in Texas in the last election, they're ready to keep going, and they're just waiting to see where they can focus their efforts," Siegel said.

Siegel was on leave from his position as assistant city attorney during the 2018 campaign, but said he would resign in a couple weeks. Siegel released a campaign video Sunday titled, "We’re Still Running."

"I believe that to win this race, it really requires a year-round commitment," Siegel said. "We can't just show up in communities on the eve of the election and make the case that the Democratic Party is going to improve their lives; rather, we need to show it year-round."

For Siegel, that case involves supporting Democratic legislators representing districts within the 10th Congressional District in their efforts to pass bills and coordinating Democratic activism in the congressional district.

McCaul was chairman of the House Homeland Security Committee for six years. Earlier this month, he became the top-ranked Republican on the House Foreign Affairs Committee.

McCaul has not announced a re-election campaign for 2020. He could not be reached for comment.