Paul Ryan made a generational pitch for fresh leadership on Wednesday, slamming the Obama administration with these words: “Fear and division is all they’ve got left.”

Stepping into the national spotlight at the Republican convention, the vice presidential nominee wasted no time praising Mitt Romney’s “character and decency.” Nor did he wait long to introduce his cute children in the audience, or describe himself as the son of a small-town lawyer also named Paul.

It could not be described as an electrifying speech—Ryan isn’t the barn-burner type—but his plain-spoken, Midwestern style played well in the Tampa arena. True to his reputation as one of the GOP’s leading intellectuals, it was something of a wonky speech sprinkled with folksy references—such as one to his home town of Janesville, Wisc., where “a lot of guys I went to high school with” worked at a GM plant that shut down.

How much the congressman’s appearance helped Romney is not clear. But what is beyond debate is that he has established himself, in marked contrast to Sarah Palin four years ago, as a credible contender for the office that is, in the old cliché, a heartbeat from the presidency.

The convention took an obligatory bow toward foreign policy with John McCain and Condoleezza Rice, despite the fact that Romney rarely talks about subject. McCain, the party’s 2008 nominee, gave a muscular address in which he called for greater U.S. intervention for freedom fighters abroad—a stance that Romney has not embraced in a number of specific instances.

Ryan delivered the most sustained attack on Obama that has been heard in Tampa, but it was policy-based, not personal. The frequent applause suggested the delegates have been hungering for just such an indictment. (Rush Limbaugh has been unhappy with that tone, saying he is “literally going insane” because “a bunch of wimps” don’t have the guts to assail Obama by name.)

Ryan accused Obama of trying to “dodge and demagogue”  the debt problem he created. He framed the ticket’s agenda as a bold challenge to fix the country’s problems: “We will not duck the tough issues—we will lead.” And he took the obligatory shot at Obamacare as a law that “has no place in a free country.”

The author of a plan to turn Medicare into a voucher program, which passed the House, also doubled down on health care and the elderly. He repeated a cynically selective attack by assailing the president for cutting $716 billion from Medicare—without acknowledging that his own budget assumes the same savings, but approaches the matter differently. Legions of fact-checkers have not persuaded Ryan to drop the line.

This was a crucial moment for Romney’s running mate, a congressman who has never run outside his Wisconsin district and who is far better known to party activists and journalists than to the general public.

While Romney’s speech Thursday night is the main event, it’s hard to overstate how important Ryan’s role is to a party that regards him as a hero. He is viewed as a truth-teller who would slash the size of government, although his deficit-fighting fervor lags when it comes to tax cuts and trimming defense spending.

In the end, Ryan portrayed himself and Romney as two earnest men from the heartland who just happen to have different songs on their iPods. He did nothing to hurt himself in Tampa, and in fact, if the ticket falls short, Paul Ryan already has a leg up for 2016.