Who is Barack Obama? What have voters been telling Rasmussen Reports about the man who has energized his fellow Democrats and tonight officially becomes the first African-American presidential candidate of a major U.S. political party?

At least six out of 10 voters say he’s a liberal, and over half say he will opt for big government solutions to the nation’s problems. But then 68% think his Republican opponent John McCain is conservative, and half believe he will enact policies just like President Bush’s.

In our most recent polling on the issues last week, 52% expect government spending to rise under a President Obama, and slightly more (54%) think taxes will go up.

Forty-plus percent of voters routinely tell us that the 47-year-old first-term senator from Illinois is too inexperienced to be president, although slightly more disagree.

Nationally, the Rasmussen Reports daily Presidential Tracking Poll which has been close for weeks now shows hints of a building convention bounce for Obama.

Voter trust on most major issues seesaws back and forth between McCain and Obama. This week, for example, voters give McCain the edge on handling the economy 48% to 42%. A week ago they trusted Obama more 46% to 44%. Bottom line is that neither man has connected with voters enough on the economy to obtain a sustained advantage.

However, voters consistently give Obama the edge in terms of trust in the areas of ethics and reducing government corruption, the environment, health care and education.

Only on national security issues and the war in Iraq do voters regularly trust McCain more.

Still, with over half of voters saying the most important goal in Iraq is to bring the troops home versus around 40% who believe winning the war is key, Obama is more in synch with the majority. Last week 68% said it is at least somewhat likely that Obama will bring the troops home in his first term, while only 39% believed that of McCain. Fifty-one percent (51%) believed it at least somewhat likely that the United States would win the war in Iraq in McCain’s first four years in office, as opposed to only 30% who thought that of Obama.

With voters in general showing record levels of confidence in how America is doing in the War on Terror and, by extension, Iraq, the focus increasingly is on domestic issues, particularly energy. Record gas and oil prices, and their impact on the overall economy, are forcing many voters to rethink long-held positions.

McCain stirred up things in early June with his call for lifting the longtime ban on offshore oil drilling as one way to fight high prices. This position, initially opposed by national Democrats and their nominee, has been credited with helping the Republican stay competitive in the presidential race against the younger and more charismatic Obama. In our polling, over 60% now support offshore drilling.

By substantial margins, voters believe that McCain’s top priority is finding new sources of energy while Obama is more focused on reducing the amount of energy we consume.

Obama’s call for more electric cars, solar power and wind power is supported by at least one-third of voters, but as in virtually all the topics discussed here Democrats not surprisingly are more enthusiastic than Republicans and unaffiliated voters.

Perhaps as a reflection of the historical nature of Obama’s nomination, about 45% of voters say the Democrat views society as unfair and discriminatory, while only 12-15% believe that of McCain. A similar number in the 40s say Obama thinks U.S. society is fair and decent, as opposed to 65-70% who believe McCain feels that way.

When asked who will make a better leader and whose values are closest to your own, voters generally give McCain the edge by several percentage points. Changing that perception will perhaps be Obama’s biggest challenge in the next two months.

Just two weeks ago, 77% of voters disagreed with the proposition that there is not much difference between what the two candidates would do in office. So in voters’ minds this is definitely a horse race.