How was his presidency viewed elections of President Obama as response?

Answer 1

I think you are asking what caused the election of Barack Obama-- what was it in response to, and how did people feel about it. The country had just endured eight years of President Bush and the Republicans, and while Mr. Bush still had his fans, his presidency had become very controversial and polarizing. Many Americans from both parties were now opposed to the war in Iraq. Many felt Mr. Bush had not done a good job with the economy, and even some Republicans felt he had spent too much. There were also a number of scandals which affected prominent Republicans. People developed a lot of doubt that Mr. Bush was handling things in the right way.

It is very normal in politics, after one party has been dominant for a while, for people to decide it is time for a change, especially if the dominant party has had problems with its policies or had a number of scandals. When it came time for the election of 2008, the Republican candidate for president was John McCain. Senator McCain was admired as a war hero from the Vietnam era, but he was also seen as an older man who reminded people of President Bush's policies, and it seemed he wanted to continue those policies. Americans had decided those policies weren't working; they wanted a new direction. Barack Obama represented someone young, someone with a positive vision for the country. He promised to end the war in Iraq, and he promised he would bring a new tone of civility to Washington. After years of political fights, these promises resonated with many Americans. This does not mean everyone agreed with everything he said, but he was seen as someone who would not just continue the Bush policies. He was elected overwhelmingly, becoming the first African-American president, and someone that Americans were hopeful would make America a better country.

Of course, as often happens with a new president, many of his promises and intentions were thwarted, some were delayed, and others were kept. Mr. Obama became as polarizing a person as Mr. Bush had been (although for different reasons). But your question seems to be asking about how people viewed his election at the time, and what his election was in reaction to, and I hope I have answered that for you.