Sen. Rand Paul’s (R., Ky.) latest fundraising letter takes aim at "neocons," "war fever," and drone strikes against terrorists, a sign that he is working overtime to court his father’s isolationist base in the face of fading poll numbers.

The fundraising appeal asked supporters to chip in at least $20.16 and was posted on the presidential candidate’s Facebook page on Monday. It was written by Rand Paul’s father, former Rep. Ron Paul (R., Texas).

"[Rand is] not afraid to lay the blame for making worse the chaos we see today with ISIS and Iraq squarely at the feet of the neocons," promised Ron Paul in the letter, noting that his son opposes terrorist-killing drone strikes and mounted a campaign to "force the Patriot Act to expire."

Rand Paul blamed "neocons" for the rise of the Islamic State earlier this year, but later backed off the comment and said he could have phrased it better.

The elder Paul also warned in the fundraising letter that there was a concerted effort by both political parties to "destroy" him and his son.

"They're going all-out to destroy him just like they tried to destroy me," wrote Ron Paul. "And if they succeed, they'll go on to even more spending, spying, welfare and warfare in Washington, D.C."

Since launching his presidential campaign, Rand Paul has been keeping a relative distance from his father, who runs a conspiracy theory blog and often appears on doomsday infomercials and Kremlin TV.

The Kentucky senator has recently been struggling to gain a foothold in the Republican primary, polling in the low single digits.