Jeb Bush considers himself more conservative than both his father, former President George H.W. Bush, and his brother, former President George W. Bush.

George W. Bush's Medicare Part D program should have been paid for at the time it was passed instead of running up government spending, the former Florida governor told a campaign audience in the key early primary state of New Hampshire last week, Real Clear Politics reported.

And as he tries to establish his own conservative credentials, Jeb Bush increasingly uses his brother as a "measuring stick," the publication added. And Tim Miller, a spokesman for his campaign, did not mind acknowledging the strategy.

"Jeb has laid out plans for dismantling D.C., reforming the tax code and reforming regulations that go far beyond what was proposed in the 2000s," Miller enumerated.

In South Carolina, another critical early-primary state, however, Jeb Bush might eventually need his brother -- still highly popular with GOP supporter across the United States -- to help turn around his own low poll numbers, the Guardian noted based on an unnamed Republican operative.

"Bush is distinctly second-tier right now," the source told the British newspaper. "I follow thousands of people on Facebook, social media. I don't literally see any Bush supporters. There are a couple elected officials. But I don't know who is supporting Jeb Bush in the grassroots. People that are, you know, the five- to 10,000 top Republicans in the state -- I don't know who's supporting Jeb Bush. I don't see those people. It's shocking."

When theSkimm, a popular email newsletter, tried to push Jeb Bush to shed more light his fraternal relations, meanwhile, the former governor came up with a humorous response.

"Different than Marvin?" Bush joked when he was asked to say what differentiated him most from "his brother." Marvin, the youngest son of George H. W. Bush, is the "the runt of the litter," Jeb Bush quipped. "I'm 6-foot-4," he added.