As polls show Ben Carson catching – and even surpassing – Donald Trump, the brash businessman’s attacks against his closest challenger have intensified. His remarks could backfire for being redundant, vague and hypocritical.

While Trump has been known for direct and personal verbal lobs against his opponents in the campaign, this is the first time he has found himself faced with another outsider who has risen above him in some recent key polls. And his strategy so far has yet to have any impact on Carson as the former pediatric neurosurgeon has refused to take the bait.

On MSNBC’s Morning Joe Tuesday, Trump was quick to question Carson’s appeal, insisting that under scrutiny, it won’t continue. A “a lot of things will come out” about Carson’s record, Trump said.

Trump challenged Carson’s strict anti-abortion position, which Trump said wasn’t always the same.

“Ben was pro-abortion not so long ago as everybody has told me,” Trump said.