Jeb Bush
Jeb Bush Reuters

Republican presidential nominee Mitt Romney is set to give the biggest speech of his political career in just a few hours and former Florida Gov. Jeb Bush has advice for him -- be a little more human and show some emotion.

Thursday night will be Romney's time to ultimately assure millions of voters that he is the man who can get the U.S. economy back on track and create jobs. The problem is Democrats have been portraying Romney as an out-of-touch rich man for months, and the public's perception of the GOP's man is, indeed, along those lines.

Romney took the nomination with a low favorability rate.

A recent poll by ABC News and the Washington Post shows that only 40 percent of registered voted view Romney favorably while 51 percent see him unfavorably. In the same poll his opponent Barack Obama has a 50 percent favorable rating versus 47 percent unfavorable.

Show Your Heart

Bush, whose brother and father were presidents, urged Romney to allow people in when he speaks Thursday night.

"It's hard for him to show his heart," Bush told "Good Morning America." "I respect that. I was brought up being told not to brag, not to open up and show your frailties and show your emotions, but he has to.

"Where it matters is connecting with other people's concerns," he added. "I don't think he has to be like this New Age kind of guy all of a sudden. He's not going to be that way. It's important to connect emotionally. That gives you the chance to allow people in, then you can make your case."

Romney's convention speech is a chance for the former Massachusetts governor to lift his favorability ratings out of the slumps.

But that does not come naturally to someone who is a businessman at heart, and has built his entire case for the presidency on one issue: the economy.

When he became governor in 2003, Romney successfully closed a $3 billion budget gap in the state without increasing taxes. Surplus money was also left for the next governor and taxes were lowered more than 12 times during Romney's leadership, local reports show.

Restate Economic Message

Besides allowing people to view the Mitt Romney they have been waiting to see, Bush told CNN's Piers Morgan that the Republican nominee will need to remind voters of his economic plan.

"Lay out a compelling alternative to the mess we are in," Bush said. "It is one thing to say, Mr. President, you failed -- I think that's fair game -- that's part of politics. I think people now know that.

"We are in tough economic times and I think he needs to restate his economic message to give people hope that there is a better chance for a better life going forward," he added. "Share the Mitt Romney story. It's amazing that we live in a time where people see their candidates a lot but they don't really always get the chance to know them and I think Mitt Romney is a reserved man."