CHILMARK, Mass., Aug 15 (Reuters) - Declaring he was tired of talking about Donald Trump, President Barack Obama urged Democrats on Monday not to grow too confident about their prospects in the 2016 election despite Hillary Clinton's strong position in the race for the White House.

Obama, who is on a two-week vacation in Martha's Vineyard, an island off the coast of Massachusetts, took a short break from his relaxation time to raise money for Clinton, the Democratic presidential nominee he hopes will succeed him when he leaves office in January.

Hillary Clinton's DNC speech:

21 PHOTOS Hillary Clinton DNC speech See Gallery Hillary Clinton DNC speech Democratic U.S. presidential nominee Hillary Clinton bats balloons after accepting the nomination at the Democratic National Convention in Philadelphia, Pennsylvania, U.S. July 28, 2016. REUTERS/Mark Kauzlarich Democratic presidential nominee Hillary Clinton enjoys the balloon drop after accepting the nomination on the fourth and final night at the Democratic National Convention in Philadelphia, Pennsylvania, U.S. July 28, 2016. REUTERS/Gary Cameron Democratic presidential nominee Hillary Clinton and her husband former president Bill Clinton react to the balloon drop after she accepted the nomination on the fourth and final night at the Democratic National Convention in Philadelphia, Pennsylvania, U.S. July 28, 2016. REUTERS/Jim Young Democratic presidential nominee Hillary Clinton enjoys the balloon drop with her vice presidential running mate Senator Tim Kaine after accepting the nomination on the fourth and final night at the Democratic National Convention in Philadelphia, Pennsylvania, U.S. July 28, 2016. REUTERS/Gary Cameron Democratic presidential nominee Hillary Clinton and her husband former president Bill Clinton react to the balloon drop after she accepted the nomination on the fourth and final night at the Democratic National Convention in Philadelphia, Pennsylvania, U.S. July 28, 2016. REUTERS/Jim Young TPX IMAGES OF THE DAY Democratic U.S. presidential nominee Hillary Clinton celebrates with balloons after she accepted the nomination on the last night of the Democratic National Convention in Philadelphia, Pennsylvania, U.S. July 28, 2016. REUTERS/Mike Segar Democratic presidential nominee Hillary Clinton celebrates among balloons after she accepted the nomination on the fourth and final night at the Democratic National Convention in Philadelphia, Pennsylvania, U.S. July 28, 2016. REUTERS/Jim Young Democratic presidential nominee Hillary Clinton and her vice presidential running mate Senator Tim Kaine celebrate among balloons after she accepted the nomination on the fourth and final night at the Democratic National Convention in Philadelphia, Pennsylvania, U.S. July 28, 2016. REUTERS/Jim Young Democratic U.S. presidential nominee Hillary Clinton hugs her husband former president Bill Clinton after accepting the nomination on the fourth and final night at the Democratic National Convention in Philadelphia, Pennsylvania, U.S. July 28, 2016. REUTERS/Brian Snyder Democratic U.S. presidential nominee Hillary Clinton bats balloons after accepting the nomination at the Democratic National Convention in Philadelphia, Pennsylvania, U.S. July 28, 2016. REUTERS/Mike Segar TPX IMAGES OF THE DAY Democratic presidential nominee Hillary Clinton (L) waves with Anne Holton, wife of vice presidential running mate Senator Tim Kaine (Back, R) and her husband former president Bill Clinton after accepting the nomination at the Democratic National Convention in Philadelphia, Pennsylvania, U.S. July 28, 2016. REUTERS/Mike Segar Democratic presidential nominee Hillary Clinton walks with her vice presidential running mate Senator Tim Kaine during the balloon drop after accepting the nomination on the fourth and final night at the Democratic National Convention in Philadelphia, Pennsylvania, U.S. July 28, 2016. REUTERS/Gary Cameron Democratic Presidential candidate Hillary Clinton (L) and Democratic Vice Presidential candidate Tim Kaine (R) celebrate with loved ones and supporters after her acceptance speech at the 2016 Democratic National Convention July 28, 2016 in Philadelphia, Pennsylvania. / AFP / Brendan Smialowski (Photo credit should read BRENDAN SMIALOWSKI/AFP/Getty Images) Democratic Presidential candidate Hillary Clinton and her husband former US President Bill Clinton watch falling balloons during the 2016 Democratic National Convention July 28, 2016 in Philadelphia, Pennsylvania. / AFP / Brendan Smialowski (Photo credit should read BRENDAN SMIALOWSKI/AFP/Getty Images) Democratic presidential nominee Hillary Clinton stands with her husband, former president Bill Clinton, after accepting the nomination on the final night of the Democratic National Convention in Philadelphia, Pennsylvania, U.S. July 28, 2016. REUTERS/Mike Segar Balloons come down on Democratic presidential nominee Hillary Clinton and running mate Tim Kaine at the end of the fourth and final night of the Democratic National Convention at Wells Fargo Center on July 28, 2016 in Philadelphia, Pennsylvania. / AFP / SAUL LOEB (Photo credit should read SAUL LOEB/AFP/Getty Images) Democratic presidential nominee Hillary Clinton celebrates among balloons after she accepted the nomination on the fourth and final night at the Democratic National Convention in Philadelphia, Pennsylvania, U.S. July 28, 2016. REUTERS/Jim Young TPX IMAGES OF THE DAY UNITED STATES - JULY 28: Hillary Clinton reacts to the pyrotechnics display as Bill Clinton joins her on stage after her acceptance speech for the nomination to be President at the Democratic National Convention in Philadelphia on Thursday, July 28, 2016. (Photo By Bill Clark/CQ Roll Call) UNITED STATES - JULY 28: Bill Clinton hugs Hillary Clinton after her acceptance speech for the nomination to be President at the Democratic National Convention in Philadelphia on Thursday, July 28, 2016. (Photo By Bill Clark/CQ Roll Call) UNITED STATES - JULY 28: Democratic nominees for President and Vice President Hillary Clinton and Sen. Time Kaine on stage at the end of the Democratic National Convention in Philadelphia on Thursday, July 28, 2016. Hillary Clinton became the first woman to win the nomination of a major political party for President of the United States. (Photo By Bill Clark/CQ Roll Call) UNITED STATES - JULY 28: Democratic Presidential nominee Hillary Clinton arrives to address the crowd at the Wells Fargo Center in Philadelphia, Pa., on the final night of the Democratic National Convention, July 28, 2016. (Photo By Tom Williams/CQ Roll Call) Up Next See Gallery Discover More Like This HIDE CAPTION SHOW CAPTION of SEE ALL BACK TO SLIDE

Clinton leads Trump in opinion polls, and the Republican nominee's campaign has suffered following remarks he made denigrating the parents of a fallen Muslim American soldier and charging that Obama was the founder of the Islamic State militant group.

The president warned his party, however, to maintain a sense of urgency until the Nov. 8 election.

"If we are not running scared until the day after the election, we are going to be making a grave mistake," Obama told some 60 donors who contributed $10,000 each to attend the fundraiser at a private home on the island.

Photos of Hillary Clinton and Barack Obama at the DNC:

11 PHOTOS Hillary Clinton and Barack Obama at the DNC See Gallery Hillary Clinton and Barack Obama at the DNC U.S. President Barack Obama (L) and Democratic presidential candidate Hillary Clinton wave to the crowd after the President spoke at the Democratic National Convention in Philadelphia, Pennsylvania, U.S. July 27, 2016. REUTERS/Brian Snyder Democratic presidential nominee Hillary Clinton hugs U.S. President Barack Obama as she arrives onstage at the end of his speech on the third night of the 2016 Democratic National Convention in Philadelphia, Pennsylvania, U.S., July 27, 2016. REUTERS/Jim Young Democratic presidential nominee Hillary Clinton joins U.S. President Barack Obama onstage after his remarks on the third night of the Democratic National Convention in Philadelphia, Pennsylvania, U.S. July 27, 2016. REUTERS/Jonathan Ernst TPX IMAGES OF THE DAY Democratic presidential nominee Hillary Clinton hugs U.S. President Barack Obama as she arrives onstage at the end of his speech on the third night of the 2016 Democratic National Convention in Philadelphia, Pennsylvania, U.S., July 27, 2016. REUTERS/Jim Young U.S. President Barack Obama and Democratic presidential nominee Hillary Clinton appear onstage together after his speech on the third night at the Democratic National Convention in Philadelphia, Pennsylvania, U.S. July 27, 2016. REUTERS/Carlos Barria Democratic presidential nominee Hillary Clinton greets U.S. President Barack Obama as she arrives onstage at the end of his speech on the third night of the 2016 Democratic National Convention in Philadelphia, Pennsylvania, U.S., July 27, 2016. REUTERS/Jim Young Democratic presidential nominee Hillary Clinton greets U.S. President Barack Obama as she arrives onstage at the end of his speech on the third night of the 2016 Democratic National Convention in Philadelphia, Pennsylvania, U.S., July 27, 2016. REUTERS/Jim Young U.S. President Barack Obama and Democratic presidential nominee Hillary Clinton appear onstage together after his speech on the third night at the Democratic National Convention in Philadelphia, Pennsylvania, U.S. July 27, 2016. REUTERS/Mark Kauzlarich U.S. President Barack Obama and Democratic presidential nominee Hillary Clinton appear onstage together after his speech on the third night at the Democratic National Convention in Philadelphia, Pennsylvania, U.S. July 27, 2016. REUTERS/Mike Segar U.S. President Barack Obama and Democratic presidential nominee Hillary Clinton appear onstage together after his speech on the third night at the Democratic National Convention in Philadelphia, Pennsylvania, U.S. July 27, 2016. REUTERS/Mike Segar U.S. President Barack Obama and Democratic presidential nominee Hillary Clinton appear onstage together after his speech on the third night at the Democratic National Convention in Philadelphia, Pennsylvania, U.S. July 27, 2016. REUTERS/Mike Segar Up Next See Gallery Discover More Like This HIDE CAPTION SHOW CAPTION of SEE ALL BACK TO SLIDE

"If we do our job, then Hillary will be elected president of the United States. But if we do not do our jobs, then it's still possible for her to lose."

The remarks could foreshadow the president's role this fall in encouraging get-out-the-vote efforts for Clinton, his former secretary of state.

Obama has made clear his disdain for Trump, calling him unqualified for the White House. He told the donors he was tired of talking about Clinton's rival.

"I don't have to make the case against her opponent, because every time he talks he makes the case against his own candidacy," Obama said.

The president is expected to campaign heavily for Clinton in October.

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