Paul Ryan and Ted Cruz are both popular speakers on the conservative dinner circuit. They have both taken their shows on the road to such familiar destinations as New Hampshire and Iowa. They could both be on the presidential ballot in those states in early 2016. Both have deep roots in the conservative movement.

The similarities end there. At the relatively young age of 43, Ryan has been in Congress for 14 years. Cruz, almost a year younger, arrived in Washington as a senator in January. Ryan is loyal to House Speaker John Boehner, although he is probably the Republican who could most easily replace him, and backed George W. Bush’s costly experiments in “compassionate conservatism,” despite his reputation as a budget hawk.

Cruz vexes the Republican leadership in both houses of Congress. His defund Obamacare strategy has upended both Boehner and Senate Minority Mitch McConnell’s carefully laid plans. Some Republicans voted with Cruz on defunding almost as much to spite him—let’s see what he can really accomplish in Harry Reid’s Senate—as to express solidarity with him.

Ryan is broadly well-liked by his GOP colleagues, even among moderates who worry his proposed entitlement reforms go too far and Tea Partiers who don’t think he goes far enough. Cruz elicits complaints and eye rolls even from Hill Republicans who substantially agree with him, though only occasionally on the record, as his stock rises with the conservative base.

In recent years, Ryan has risen to chairman of the House Budget Committee and was his party’s 2012 nominee for vice president. If high executive office isn’t in his future, a Ways and Means chairmanship could be. Cruz gleefully throws bombs from the back benches, regularly flouting Senate customs. His power comes from his Tea Party supporters, not from his committee assignments.

Yet Cruz has achieved influence comparable to Ryan’s and is still ascendant. (Though Ryan hasn’t exactly rushed to Cruz’s side.) Here the differences between the two of them may contain useful information about the shifting center of gravity within the Republican Party.

When Ryan was first elected to the House in 1998, the conservative backbenchers pressing for deeper spending cuts and the abolition of government agencies had been decisively beaten. The most prominent example of a Republican rebelling his way to the top was soon-to-be-former House Speaker Newt Gingrich—the very leader who had just crushed the conservative hardliners.

Unlike a lot of the rabble-rousers of 1994, Ryan hailed from a swing district in the Democratic-leaning state of Wisconsin (where the staunchly liberal Russ Feingold won a second Senate term by beating class of ’94 alum Mark Neumann). His mentor was Jack Kemp, who had represented a blue-collar district in New York and was focused on expanding the Republican Party. Ryan’s conservatism lacked a Sunbelt feel.

Following the leadership was a logical path forward for a young Republican congressman at that time, and that’s what Ryan usually did. He pursued his more controversial budget work on the side as he gradually rose through the ranks, eventually reaching the point where he could get the GOP caucus to embrace his Medicare blueprint as its own.

But while Ryan was advancing through more conventional routes, the backbenchers began to reassert themselves. Mike Pence was elected to the House just two years after Ryan. Unlike Ryan, he voted against both No Child Left Behind and the Medicare prescription-drug benefit. Far from damaging his career, Pence managed to become chairman of the House Republican conference and is today governor of Indiana.

Jim DeMint was elected to the House in 1998, the same year as Ryan. He too was initially a team player, but he grew so disenchanted with the party leadership that he became more vocal in his dissent than Pence. He felt that the president threatened him over the prescription-drug benefit, and proceeded to vote against it anyway.

Once elected to the Senate in 2004, he became something of a kingmaker by supporting successful primary challenges to leadership-approved GOP senators—including some incumbents. DeMint is now president of the Heritage Foundation, which many observers believe he is pushing further in the direction of conservative activists.

Perhaps the most striking example is Ron Paul, the backbencher’s backbencher during two stints in Congress. He voted against the Bush administration and the Republican leadership even on foreign policy, at a time when it was unheard of to do so. Through a GOP presidential campaign that initially polled at just 1 percent nationally, he became the leader of a vibrant national movement.

Cruz was endorsed by both DeMint and Paul, and he owes his Senate seat to a victory over a leadership favorite—the sitting lieutenant governor of Texas—in a Republican primary. He is partly a nonconformist and partly someone committed to convincing other Republicans to conform to his orthodoxies.

On foreign policy, Ryan is reliably hawkish. Cruz has been more inclined to associate himself with Rand Paul, though his grilling of Chuck Hagel and rhetoric about Iran suggest he is keeping his options open. He has described himself as being “somewhere in between” Paul and John McCain.

Both Ryan and Cruz have succeeded in swaying the House to vote in favor of things that once would have seemed inconceivable. In fact, the party as a whole is now branded with Ryan on Medicare and Cruz on Obamacare. But can either of them shape the policies of the nation?

The first right-of-center politician who does may win the Republican future.

W. James Antle III is editor of the Daily Caller News Foundation and author of Devouring Freedom: Can Big Government Ever Be Stopped?