Changes

| term_start=January 1, 1991  

| term_start=January 1, 1991  

| term_end=December 31, 2001

| term_end=December 31, 2001

| predecessor=Andres "Andy" Ramos

| predecessor=[[Andres Ramos|Andres "Andy" Ramos, Jr.]]

| successor=[[Louis H. Bruni]]

| successor=[[Louis H. Bruni]]

| birth_date=July 25, 1937

| birth_date=July 25, 1937

In 1978, the [[Democratic Party|Democrat]] Martinez was elected to the Laredo City Council, a nominally nonpartisan position. At the same time, [[Aldo Tatangelo]] was elected [[mayor]] to succeed the retiring [[J. C. Martin, Jr.|J. C. "Pepe" Martin, Jr.]], of the former "Independent Club," who subsequently spent time in the Webb County Jail for theft of municipal services.<ref>{{cite web|url=http://tshaonline.org/handbook/online/articles/wmiqt|title=Independent Club|publisher=''The Handbook of Texas''|accessdate=July 27, 2020}}</ref> Martinez worked on the council to change the city government from "strong mayor" to "weak mayor" format through a new municipal charter.<ref name=bio/> After a brief time on the council, he was asked by [[U.S. President]] [[Jimmy Carter]] to head the Southwest Regional Office in Dallas of the [[Small Business Administration]]. During this stint, he lived in Dallas on weekdays but returned to Laredo most weekends.<ref name=interview/>

In 1978, the [[Democratic Party|Democrat]] Martinez was elected to the Laredo City Council, a nominally nonpartisan position. At the same time, [[Aldo Tatangelo]] was elected [[mayor]] to succeed the retiring [[J. C. Martin, Jr.|J. C. "Pepe" Martin, Jr.]], of the former "Independent Club," who subsequently spent time in the Webb County Jail for theft of municipal services.<ref>{{cite web|url=http://tshaonline.org/handbook/online/articles/wmiqt|title=Independent Club|publisher=''The Handbook of Texas''|accessdate=July 27, 2020}}</ref> Martinez worked on the council to change the city government from "strong mayor" to "weak mayor" format through a new municipal charter.<ref name=bio/> After a brief time on the council, he was asked by [[U.S. President]] [[Jimmy Carter]] to head the Southwest Regional Office in Dallas of the [[Small Business Administration]]. During this stint, he lived in Dallas on weekdays but returned to Laredo most weekends.<ref name=interview/>

In 1982, Martinez returned to Laredo to run for mayor against Tatangelo, and though he had led in the primary, he lost in the runoff election.<ref name=tamiudocument>{{cite web|url=http://www.tamiu.edu/oatah/rmendiola/documents/MercurioMartinezJr..pdf|title=Mercurio Martinez, Jr.|publisher=tamiu.edu|author=Amanda Martinez|accessdate=July 27, 2020}}</ref> In 1990, he was elected county judge, having unseated the incumbent Andres "Andy" Ramos. Though he had no [[Republican Party|Republican]] opponent in the [[general election]], former Mayor Tatangelo, at the age of seventy-seven, opposed his former mayoral rival Martinez for county judge as a write-in candidate. Martinez still prevailed with some 75 percent of the votes cast, but the county Republican leadership, headed by Esther Buckley (1948-2013), endorsed Tatangelo. After three terms as county judge, Martinez was unseated in the 2002 Democratic primary by [[Louis H. Bruni]], a departing member of the Laredo City Council from District 2. Thereafter, beginning in the fall of 2003, Martinez began teaching accounting at Texas A&M International University in Laredo.<ref name=bio/><ref>Louis H. Bruni served only one term as county judge, having been defeated in 2006 by [[Danny Valdez]], who was himself defeated after two terms by former professional [[baseball]] player [[Tano Tijerina]] in 2014. In 2018, Tijerina won a second term in the position.</ref>

In 1982, Martinez returned to Laredo to run for mayor against Tatangelo, and though he had led in the primary, he lost in the runoff election.<ref name=tamiudocument>{{cite web|url=http://www.tamiu.edu/oatah/rmendiola/documents/MercurioMartinezJr..pdf|title=Mercurio Martinez, Jr.|publisher=tamiu.edu|author=Amanda Martinez|accessdate=July 27, 2020}}</ref> In 1990, he was elected county judge, having unseated the incumbent [[Andres Ramos|Andres "Andy" Ramos, Jr.]] Though he had no [[Republican Party|Republican]] opponent in the [[general election]], former Mayor Tatangelo, at the age of seventy-seven, opposed his former mayoral rival Martinez for county judge as a write-in candidate. Martinez still prevailed with some 75 percent of the votes cast, but the county Republican leadership, headed by Esther Buckley (1948-2013), endorsed Tatangelo. After three terms as county judge, Martinez was unseated in the 2002 Democratic primary by [[Louis H. Bruni]], a departing member of the Laredo City Council from District 2. Thereafter, beginning in the fall of 2003, Martinez began teaching accounting at Texas A&M International University in Laredo.<ref name=bio/><ref>Louis H. Bruni served only one term as county judge, having been defeated in 2006 by [[Danny Valdez]], who was himself defeated after two terms by former professional [[baseball]] player [[Tano Tijerina]] in 2014. In 2018, Tijerina won a second term in the position.</ref>

In 2006, Martinez ran unsuccessfully for the Democratic nomination to represent Texas House District 42, having  been defeated by the incumbent and still serving Richard Peña Raymond of Laredo. In the primary Raymond fell .07 percent plus one vote short of an outright victory. He finished first with 11,806 votes (49.8 percent); Martinez trailed with 7,650 (32.3 percent). Two other contenders held the remaining 17.9 percent of the vote.In the runoff contest in April 2006, Raymond prevailed, 8,828 votes (57.8 percent) to Martinez's 6,456 (42.2 percent).

In 2006, Martinez ran unsuccessfully for the Democratic nomination to represent Texas House District 42, having  been defeated by the incumbent and still serving Richard Peña Raymond of Laredo. In the primary Raymond fell .07 percent plus one vote short of an outright victory. He finished first with 11,806 votes (49.8 percent); Martinez trailed with 7,650 (32.3 percent). Two other contenders held the remaining 17.9 percent of the vote.In the runoff contest in April 2006, Raymond prevailed, 8,828 votes (57.8 percent) to Martinez's 6,456 (42.2 percent).