Warren opposed the bill because of a provision that would relax a restriction on Wall Street banks. In press conferences and Senate floor speeches, Warren spoke out against the bill and encouraged others to vote against it. She also teamed up with Sen. David Vitter (R-La.) to introduce an amendment to strip out the banking provision.
Cruz used similar tactics to protest what he saw as an inadequate response in the bill to President Obama's executive actions on immigration.
But he also went further -- teaming up with Sen. Mike Lee (R-Utah) in protest. What resulted was a Saturday session that Majority Leader Harry M. Reid (D-Nev.) used to make progress on President Obama's executive branch nominees. That outcome angered many of Cruz's Republican colleagues.
Cruz finally got a point of order vote on immigration. It failed. But he made his point.
He now has a something tangible to show his conservative base as evidence of his fight against Obama's decision to halt the deportations of millions of undocumented immigrants. And he put his colleagues on the record on a major issue.
But it came at a price. That price was grumbling from Republican senators and a here-we-go-again sense among some of them who vividly remember the 2013 government shutdown and Cruz's fight against the federal health care law, which fueled it.
Warren, like Cruz, voted against final passage of the spending bill. En route to that vote, she made life more difficult for Democratic leaders -- namely Obama and Reid -- who wanted to see the bill cleared quickly, in order to avoid another government shutdown.
But she didn't raise hackles in her ranks as Cruz did in his.
"Even if people don't agree with her, she's constructive. She's not like Ted Cruz," said Sen. Charles E. Schumer (D-N.Y.) on CNN's "State of the Union" Sunday. Schumer is the third-ranking Senate Democrat.
Compare that to some of the things Cruz's GOP colleagues were saying about his strategy on Saturday. Sen. Susan Collins (R-Maine) called it "unfortunate." Sen. Jeff Flake (R-Ariz.) said, "I fail to see what conservative ends were achieved." Sen. Bob Corker (R-Tenn.) complained, "The White House is going to end up with far more nominations confirmed than they ever would have."
Cruz's main ally in his fight was Sen. Mike Lee (R-Utah), who like him, is known for bucking Republican leadership. But Warren counted House Minority Leader Nancy Pelosi (D-Calif.), a leading figure in the Democratic establishment, as an ally in her battle.
The contrast between Warren and Cruz also speaks to the different political trajectories they appear to be on. Warren has said repeatedly that she is not running for president. Cruz has been far less dismissive of the White House chatter surrounding him.
If he were to run, Cruz's core support would come a from conservative base fed up with Washington, which could care less what Collins, Flake or most other Republican senators think. They want to back an outsider -- the kind of Republican who would force a vote to make a point about immigration, even if it makes others unhappy.
In that case, his political strategy makes total sense right now.
So does Warren's, if you buy the idea that she is more likely than not to sit out the 2016 presidential race. If she is not making a play for the White House, then she is staying put the Senate. And in the orderly, hierarchical Senate, you've got to "know when to hold 'em, know when to fold 'em," to quote Kenny Rogers, lest you alienate colleagues and marginalize your power in the legislating process.
The reason why Cruz and Warren are such fascinating political figures with such passionate supporters is that there aren't really any others doing what they do from such a high-ranking position right now. You just don't see senators openly thumb their nose at the rest of their party like they do. It's novel.
But similar as they may be -- Cruz even called Warren a "friend" on Saturday -- the biggest strategic difference between the two is where they see the line and whether they are willing to cross that line to make their points.
This time, as was true before, Cruz was. Warren was not.