Sen. John McCain may have apologized for calling relative Senate newcomers Rand Paul and Ted Cruz “wacko birds,” but the Arizona Republican hasn’t given up fighting their isolationist position on U.S. foreign policy.

Paul and Cruz — from Kentucky and Texas, respectively — offered amendments during last week’s budget “vote-a-rama” with the aim of reducing foreign aid, a position that has begun to split their party. The amendment votes were tough by design, in part because they mixed popular sounding items with poison pills.

Every Democrat present voted against Paul’s symbolic effort in the wee hours of Saturday morning to allocate $16 billion for repair and replacement of structurally-deficient bridges and other domestic infrastructure projects through cuts to Energy Department loan guarantees and foreign aid spending.

McCain was one of 19 Republicans to vote against that amendment. He was joined by South Carolina Sen. Lindsey Graham and another frequent foreign aid defender, New Hampshire Sen. Kelly Ayotte. All three senators also voted against an amendment offered by Cruz that was designed to reduce foreign assistance to Egypt in order to bankroll a missile defense system on the eastern seaboard of the United States.

Paul has shown he is not afraid to criticize his political opponents on foreign assistance spending. He went so far as to run campaign ads last year through his RAND PAC against Democrats who opposed his bid to restrict foreign aid to Libya, Pakistan and Egypt. One of those targets, West Virginia Democratic Sen. Joe Manchin III, responded by holding a conference call with the typically hawkish Graham.

During that call, Graham told reporters that Paul was promoting a foreign policy stance that would help al-Qaida, because it would turn off the American aid spigot when terrorists attack embassies abroad.

After Paul led an unsuccessful, 13-hour filibuster against the nomination of John O. Brennan to head the CIA earlier this month, McCain complained that “wacko birds” like Paul, Cruz and Rep. Justin Amash, R-Mich., always get “the media megaphone.” McCain has since apologized for using the phrase, but he has not recanted floor statements in which he said the basis for Paul’s filibuster — a demand for answers about the potential use of drones on American citizens on U.S. soil — “frankly ridiculous.”

Earlier in the week, McCain told reporters the disagreement on foreign policy has long been a feature of the GOP, recalling previous battles.

“On the issue of America’s role in the world? Oh, absolutely. That fight has been going on since prior to World War II,” McCain said. “It’s always been there, and it always will be. It’s exasperated and exaggerated by bad economic times.”

He added, “We’ve always had this struggle within the Republican party going back to post-World War I when the Republicans — isolationists kept us from joining the League of Nations. The isolationists prior to World War II, which meant we were not ready — the anti-military after Vietnam … where we had a hollow army.”

Foreign aid amendments were just a few of those offered in final hour and a half of the vote-a-rama on the fiscal 2014 budget resolution. And the atmosphere grew tense as exhausted senators were asked to stay in their seats for the duration as some of the toughest amendments were brought to a vote.

Another Cruz amendment led to the least comfortable display. He offered an amendment that would create a point of order against funding the United Nations if any member nation has forced abortions. While directed at the U.N., the proposal was a thinly-veiled criticism of China’s one-child policy. That amendment forced senators to choose between supporting forced abortions or funding for nuclear weapons inspectors.

As CQ Roll Call reported Saturday, Cruz’s amendment drew sharp criticism from Sen. Mary L. Landrieu. As senators voted from their desks, the Louisiana Democrat got up from her chair and walked across the room to Cruz’s position in a rear corner to confront him directly about the offering.

Landrieu said she thought Cruz should have pushed instead for Texas to reduce or eliminate financial transactions with China, saying “that would have had a much more direct effect on what he was trying to do than take money from the U.N.”

Eight Republicans voted against the Cruz amendment, including McCain, who spent the morning effectively sharing a desk with Minority Leader Mitch McConnell, R-Ky., as Budget ranking member Jeff Sessions, R-Ala., was using the leader’s desk to manage the floor. Seated next to Cruz, Ayotte voted for his amendment. So did Graham, but he did not look pleased with the way the proceedings were going.

The votes also presented Florida Sen. Marco Rubio with a choice: Go with McCain and Graham and support an aggressive foreign policy, as the Republican has often done in recent years, or vote with Cruz and Paul in criticizing the United Nations and foreign aid.

Rubio went with Cruz and Paul, a potential 2016 rival.

All of this positioning may highlight an old expression of McCain’s that he repeated last week.

“If you’re United States senator, unless you are under indictment or detoxification, you automatically consider yourself a candidate for president of the United States,” said McCain, who was the GOP standard-bearer in 2008.

In an interview with the Dallas Morning News about his first weeks in Washington, Cruz said he thinks establishment members of both parties are making sure their actions are constitutionally-justified, a point on which Graham and McCain would be sure to differ.

“The biggest surprise has been the defeatist attitude of many Republicans in Washington. A lot of Republicans felt beaten down, and that there was nothing they could do to stop the erosion of liberty in this country,” Cruz told the newspaper, according to an edited transcript.

Steven T. Dennis contributed to this report.