"Some senators may choose to hurl insults and personal attacks," says new Republican Sen. Ted Cruz. "That's their prerogative. I have no intention of reciprocating."

Cruz wouldn't name names, but clearly "some senators" includes John McCain, the Republican Party's 2008 presidential candidate and Senate old bull, who recently called Cruz, along with colleague Rand Paul, a "wacko bird." Talk to the 42-year-old Cruz for any length of time, and it's clear he's not interested in publicly trading barbs with the Old Guard.

In fact, it hardly seems possible, given the publicity Cruz has received in his 60 days in Washington, but last week was the first time he actually spoke on the Senate floor. It's customary for new senators to hang back for a while, and Cruz did so, at least until he heard that Sen. Paul had begun what became a 13-hour filibuster over U.S. drone policy. Cruz hurried to assist, so his first words on the Senate floor were part of a filibuster -- not exactly a traditional debut.

For a man in the news a lot, Cruz has avoided plenty of press interviews and turned down Sunday show invitations. Instead of racing to the cameras, he has shaken things up mostly by doing his job as a senator.

Cruz has gotten a huge amount of coverage for his strong performances at hearings involving Chuck Hagel, guns and immigration. For whatever reason, some in the press have been amazed that a Princeton- and Harvard-educated lawyer, former solicitor general of Texas and winner of multiple cases before the U.S. Supreme Court would be good in a hearing room. He is.

Now Cruz is getting ready for another high-profile fight. This week, he will introduce an amendment he calls "Restore Growth First" as the Senate considers a continuing resolution to fund the government for the rest of the year. The amendment would cut funding for the implementation of Obamacare, at least until economic growth -- currently at a terrible 0.1 percent -- returns to its historic average of about 3.3 percent.

"My preference is to repeal Obamacare in its entirety," says Cruz. "But at a minimum, it doesn't make sense to implement Obamacare now. It would kill jobs, it would have an enormous negative impact on the economy."

Of course, actually passing such an amendment is impossible, given the Democrats' 55-seat majority in the Senate. The question is whether Cruz, his co-sponsors Mike Lee, Marco Rubio, Ron Johnson and James Inhofe, and fellow Republicans would be willing to jam up the continuing resolution -- that is, risk a government shutdown -- over Obamacare.

"I am willing to do anything possible to ensure that we get a vote on this," Cruz says. "There are a variety of procedural mechanisms that a senator can employ to get a vote. I am confident we are going to get that vote."

So the vote itself is the important thing. But even pushing for a vote has exposed some serious Republican divisions on continuing the fight against Obamacare. In the House, the GOP leadership wouldn't allow a vote on a defund-Obamacare measure before passing a continuing resolution last week. And at a meeting of Senate Republicans recently, several lawmakers spoke out against Cruz's plan, with some raised voices. Obamacare is a reality, one lawmaker argued; there's just been an election that was in part a referendum on it, and Republicans lost.

To Cruz, opposing Obamacare, even after it has been passed by Congress, signed by the president and upheld by the Supreme Court, is about sticking to principles. "On the merits, I think Republicans are united that Obamacare is a bad idea," he explains. "There are strategic differences as to which battles we should fight when. And I understand those differences. But I also think Republicans need to present a clear contrast to the Obama administration, and that contrast needs to be between policies that promote economic growth and expand opportunities -- and continued spending, taxes, debt and regulation."

A clear sign that Cruz has moved the needle is the stance of Senate Minority Leader Mitch McConnell. In the past, McConnell has opposed some efforts to defund Obamacare, fearing political consequences. This time, McConnell released a statement saying that he "looks forward to supporting" Cruz's amendment. McConnell's words had the feel of a man getting out of the way of an ongoing train.

In the end, don't look for Ted Cruz to defund Obamacare; the minority party can't do that. But do look for him to take one more step forward in the fastest-moving Senate career in quite a while.

Byron York, The Examiner's chief political correspondent, can be contacted at byork@washingtonexaminer.com. His column appears on Tuesday and Friday, and his stories and blog posts appear on washingtonexaminer.com.