Anything involving junior Texas Senator Ted Cruz is likely to invoke some level of toxic response from Senator John McCain of Arizona and his secondary outlet of public communication, Senator Lindsey Graham of South Carolina.

That Senator McCain harbors a grudge against “the Bushies” for the South Carolina primary defeat that ended his presidential run in 2000 is the worst kept secret in Washington. Having “his” candidate lose in his home state was also a blow to Graham. Known for his long memory, some Senate staffers joke the “R” behind McCain’s name is for “revenge.” Other quip Lindsey Graham is “the senator from McCain.”

You’d think they’d be over it, but never has their ax grinding against former George W. Bush allies been more obvious and counter-productive than over the last few months.

Ted Cruz was a key Bush campaign staffer in 2000. Primarily a legal advisor, he also provided domestic policy advice and served as a contact for movement conservatives. A brilliant legal mind, Cruz was a critical asset to Bush’s Florida recount team. Ted was well-liked and respected among campaign staff, and like Karl Rove, known to perform congressional district voter math in his head.

Including, no doubt, for the 2000 South Carolina presidential primary.

The phrase “if you want a friend in Washington, buy a dog” attributed to President Harry S. Truman remains true, but the Senate has spawned genuine friendships. Indiana Republican Senator Richard Lugar and Vermont’s liberal Democrat Patrick Leahy enjoy a long friendship despite ideological differences. The late Senators Daniel Inouye (D-HI) and Ted Stevens (R-AK) were vastly different in temperament and voting but each considered the other a brother.

The friendship between John McCain and Lindsey Graham started during the1999 Clinton impeachment hearings when Graham served on the House Judiciary Committee and was liaison to the Senate. They hit it off immediately, and developed a deep, personal friendship.

That they support each other through re-election campaigns, Senate policy battles, and any private challenges is laudable. That McCain seems to use Graham as a battering ram against people he does not like is not.

In 2001, former presidential candidate McCain’s refusal to fully support President Bush’s tax reform package led to only temporary tax cuts, which in turn contributed to the fiscal cliff. This put McCain at loggerheads with American taxpayers’ most powerful advocate, Grover Norquist of Americans for Tax Reform, author of the Taxpayer Protection Pledge. Norquist also supported Bush in 2000, and worked closely with the Bush White House to support its tax cut agenda.

When fears arose during recent fiscal cliff negotiations that Senate Republicans might raise taxes, Senate insiders muttered McCain was privately giddy over the possibility of GOP pledge-breakers, but it was Graham thrown in front to lead Republicans over the pledge-violation cliff.