Democratic presidential candidate Joe Biden on Monday endorsed Texas House candidate Eliz Markowitz, becoming the latest presidential hopeful to get involved in a pivotal January Fort Bend County special election.

The former vice president’s endorsement follows presidential candidate Michael Bloomberg’s visit to the district late last month, when he canvassed door to door with Markowitz. Former presidential candidate Beto O’Rourke also campaigned with Markowitz before he ended his White House bid, and has remained active in the district since then.

The state House seat, left vacant since Republican John Zerwas retired in late September, has captured the attention of national and state Democrats, who view the Fort Bend district as a key pickup opportunity amid their broader effort to gain control of the Texas House.

In the first round of the special election, Markowitz — the lone Democratic candidate — finished first but did not secure a majority of the votes. She tallied 39 percent, while Republican Gary Gates received 28 percent. The runoff between Markowitz and Gates is set for Jan. 28.

In a statement, Biden cited Markowitz’s background as an educator and her support for “access to health care and quality public education.”

“I’m from a family of teachers and I know the real deal: Not only is Eliz an educator and activist – she’s the kind of fighter who will bring heart and smarts to the statehouse and to communities across Texas and at home in Fort Bend County,” Biden said.

Markowitz cast Biden’s endorsement as a sign of momentum and said his support is “truly humbling.” A recent internal poll showed Markowitz and Gates in “a dead heat,” according to Markowitz’s campaign.

Gates, a businessman, has been endorsed by Gov. Greg Abbott, U.S. Rep. Pete Olson, R-Sugar Land, and Republican Fort Bend County Sheriff Troy Nehls, among other local Republicans.

Though Democrats are optimistic about flipping the district, Republicans have noted that the six GOP candidates combined for 61 percent of the vote in the first round. Zerwas won re-election by 8 percentage points in 2018, while Republican U.S. Sen. Ted Cruz edged O’Rourke by 3 points in the district.

Since ending his presidential campaign, O’Rourke has continued to campaign for Markowitz, visiting the district last month to block walk with her shortly before he announced the launch of a political action committee aimed at electing Democrats in battleground state House races.

Bloomberg, meanwhile, has ramped up his campaign operations in Texas, with his visit to the Houston area last month marking his second trip to the state since he launched his campaign in late November. A Dec. 11 CNN poll showed Biden leading the Democratic field in Texas with 35 percent, followed by U.S. Sen. Bernie Sanders with 15 percent. Bloomberg registered 5 percent support in the poll.