Ben Carson plans May 4 Detroit announcement

If Carson does kick off a presidential bid, as expected, his announcement would add a political newcomer and African-American candidate to the rapidly growing Republican field.

This month the presidential race kicked off in earnest with three freshmen GOP senators — Ted Cruz of Texas, Rand Paul of Kentucky and Marco Rubio of Florida — launching their bids, and former Secretary of State Hillary Clinton becoming the first Democrat to make her presidential campaign official.

The retired neurosurgeon has been traveling the nation over the past six months, giving paid speeches and meeting with supporters to gauge interest in a bid. He recently traveled to Iowa and New Hampshire, and spoke last weekend at the National Rifle Association's meeting in Tennessee.

Carson's relative political inexperience, however, hasn't turned him away from the campaign — if he runs, he'll look to make it an asset, framing himself as a common-sense alternative to the broken policies of Washington politicians.

And recent polls indicate it's too early to count him out. In the Real Clear Politics average of polls, Carson surveys right in the middle of the potential GOP field, ahead of more seasoned or better-known GOP contenders like former Arkansas Gov. Mike Huckabee or Rubio, and he took fifth place with 9% support in the last CNN/ORC survey, conducted in March.

Still, that's a marked decline from late February, when he was polling in the top three of the pack, indicating he still has some work to do in proving his credibility with voters.