Changes

On November 5, 2002, Mercer defeated the [[Democrat]] Raul Prado for the right to succeed the retiring five-term Democrat Representative John Amos Longoria. Mercer polled 12,703 (59 percent) to Prado's 8,138 (41 percent).<ref>{{cite web|url=http://elections.sos.state.tx.us/elchist95_state.htm|title=2002 General Election|date=November 5, 2002|publisher=Texas Secretary of State|accessdate=February 23, 2016}}</ref> In the House, Mercer served on the Higher Education, House Administration, and Transportation committees.<ref name=tlrl/>

On November 5, 2002, Mercer defeated the [[Democrat]] Raul Prado for the right to succeed the retiring five-term Democrat Representative John Amos Longoria. Mercer polled 12,703 (59 percent) to Prado's 8,138 (41 percent).<ref>{{cite web|url=http://elections.sos.state.tx.us/elchist95_state.htm|title=2002 General Election|date=November 5, 2002|publisher=Texas Secretary of State|accessdate=February 23, 2016}}</ref> In the House, Mercer served on the Higher Education, House Administration, and Transportation committees.<ref name=tlrl/>

In 2003, Mercer was named "Legislator of the Year" by the San Antonio Police Officer’s Association. He is a former member of the Texas Homeland Security Council and formerly served on the Texas State Republican Executive Committee.<ref name=sboe/> On November 2, 2004, Mercer lost by 498 votes his bid for a second term in the House. He received 19,209 votes (49.4 percent) to 19,707 (50.6 percent) for the Democrat David McQuade Leibowitz.<ref>{{cite web|url=http://elections.sos.state.tx.us/elchist114_state.htm|title=2004 General Election|date=November 2, 2004|publisher=Texas Secretary of State|accessdate=February 22, 2016}}</ref>

In 2003, Mercer was named "Legislator of the Year" by the San Antonio Police Officer's Association. He is a former member of the Texas Homeland Security Council and formerly served on the Texas State Republican Executive Committee.<ref name=sboe/> On November 2, 2004, Mercer lost by 498 votes his bid for a second term in the House. He received 19,209 votes (49.4 percent) to 19,707 (50.6 percent) for the Democrat David McQuade Leibowitz.<ref>{{cite web|url=http://elections.sos.state.tx.us/elchist114_state.htm|title=2004 General Election|date=November 2, 2004|publisher=Texas Secretary of State|accessdate=February 22, 2016}}</ref>

In 2006, Mercer rebounded politically to unseat fellow Republican Dan Montgomery in the race for the Texas Board of Education. After an indecisive [[primary election]], Mercer prevailed in a runoff contest, 13,359 votes (61.4 percent) to 7,776 (38.6 percent).<ref>{{cite web|url=http://elections.sos.state.tx.us/elchist125_state.htm|title=2006 Republican Party Primary Runoff Election|date=April 11, 2006|publisher=Texas Secretary of State|accessdate=February 23, 2016}}</ref> In the [[general election]], Mercer defeated the [[Libertarian Party]] candidate, Bill Oliver, 234,807 (71.1 percent) to 95,406 (28.9 percent). No Democrat filed for the seat that year.<ref>{{cite web|url=http://elections.sos.state.tx.us/elchist127_state.htm|title=2006 General Election|date-November 7, 2006|publisher=Texas Secretary of State|accessdate=February 22, 2016}}</ref>

In 2006, Mercer rebounded politically to unseat fellow Republican Dan Montgomery in the race for the Texas Board of Education. After an indecisive [[primary election]], Mercer prevailed in a runoff contest, 13,359 votes (61.4 percent) to 7,776 (38.6 percent).<ref>{{cite web|url=http://elections.sos.state.tx.us/elchist125_state.htm|title=2006 Republican Party Primary Runoff Election|date=April 11, 2006|publisher=Texas Secretary of State|accessdate=February 23, 2016}}</ref> In the [[general election]], Mercer defeated the [[Libertarian Party]] candidate, Bill Oliver, 234,807 (71.1 percent) to 95,406 (28.9 percent). No Democrat filed for the seat that year.<ref>{{cite web|url=http://elections.sos.state.tx.us/elchist127_state.htm|title=2006 General Election|date-November 7, 2006|publisher=Texas Secretary of State|accessdate=February 22, 2016}}</ref>