Locally, although they came out with more votes than the Republican Party, they lost about 20% of the voters who voted in 2016 going from 10,397 votes in 2016 for Hillary Clinton to 8,324 votes in 2020 for Joe Biden.
Meanwhile, the Republican Party had a humongous increase in their voter base going from 2,816 votes in 2016 to 6,881, in 2020 or a + 144% growth.
That also occurred in many other counties along the Texas/Mexico border where one would imagine things to play out very differently. 
In 28 counties across South Texas or near the border, Biden was victorious but by about half of the vote margin that Hillary Clinton did so in 2016. 
Down in the Rio Grande Valley, Biden's underperformance was most noticeable as he carried Cameron, Starr, Willacy, and Hidalgo counties by 15 points after Clinton won them by 39 points in 2016. 
The change was felt in Zapata County where Trump had lost in 2016 but won it this time by approximately 5 percentage points. 
The electoral topography change can be attributed to many things and is something that will have Political pundits talking and arguing for years to come. 
In Maverick County, you can clearly see a change. Looking at the 3 past Presidential Elections you can see how the GOP gained ground in a community that is predominant Hispanic and majority Democrat.
In 2012 the Republican Party Ticket comprised of Mitt Romney and Paul Ryan garnered only 2,171 votes as compared to Democrats Barack Obama and Joe Biden who had 8,303.
Jump ahead to 2016 and Republican Party nominee Donald Trump and Mike Pence received 2,816 votes locally.
In that 4-year span the Republican Party grew their voter base in Maverick County by + 29.7%.
The Democratic Party went from
8,303 in 2012 to10,397 in 2016 or a + 25% growth.
In 2020 for some reason that Democratic growth dissipated and decreased by -19.9 percent going from 10,397 votes in 2016 to 8,324 in the 2020 presidential election.
The Republican Party grew their voter base in 2020 by +144 percent going from 2, 816 votes in 2016 to
6,881 in 2020.
Candidate Biden ended up winning Maverick County by 9 points. Back in 2016 Hillary Clinton defeated Trump in a 56 point blowout.
While the increase in GOP voting and decrease in Democratic voting will for years be a contentious point for Political pundits, local elections are only interesting when you have both sides of the railroad tracks participating.  Especially with the vast difference in ideologies between the two parties.