Today in the Morning Line:

-From work to the social safety net to 529s, Jeb makes the case for conservatism

-Bush confronts his last name, but his still has those two other big challenges

-The GOP has a new front runner: Scott Walker

The ‘fire in the belly’: One of the potential criticisms of Jeb Bush as a candidate is that he doesn’t have the “fire in the belly,” that he’s been out of the game. Well, he was no Fred Thompson at his speech and following Q&A Wednesday at the Detroit Economic Club. Bush came across as a man very much engaged and, above all, ready to make a robust case for conservatism, one that Mitt Romney and Paul Ryan failed to do. He may have been a little stilted stylistically on TelePrompTer and much better in the Q&A, but he signaled that a third Bush presidential campaign, if he embarks on one, would be, in part, a crusade against liberalism, in particular liberal economic theory — and he won’t be afraid to take the message to places Republicans have been accused of overlooking. “I say: Let’s go where our ideas can matter most, where the failures of liberal government are most obvious,” Bush said of cities like Detroit. “Let’s deliver real conservative success.”

Taking on the ‘progressive and liberal mindset’: He accused government and, by extension, liberals of “degrading the value of work,” accused them of creating “welfare programs and tax rules that punish people with lost benefits and higher taxes for moving up those first few rungs of the economic ladder.” And, he added, “Instead of a safety net to cushion our occasional falls, they have built a spider web that traps people in perpetual dependence. … The progressive and liberal mindset believes that to every problem there is a Washington D.C. solution.” He also held up the president’s willingness to cut 529 plans as emblematic, as again “an instructive lesson in the liberal and progressive mindset. Saving for college is the responsible thing to do. But instead of embracing 529s, the liberals moved to tax them.”

That last name issue: Jeb took on the issue of his last name head on. “If I have any degree of self-awareness, this would be the place where it might want to be applied,” he said. He harkened back to his failed 1994 campaign and noted that in his winning 1998 campaign, he went to 250 schools. “By the end of that journey,” he said, “people knew that I was more than just the brother of George W. and the son of my beloved dad. I was my own person. I earned it by working hard to connect with people on a level that truly mattered. I know for a fact that if I’m going to beyond the consideration, then I’m going to have to do it on my own.”

Those other two elephants in the room: Bush tried to make an economic and moral argument for immigration, something we’re going to hear a whole lot more about. “The American experience works when people embrace a set of shared values,” he said, “it doesn’t work when we divide ourselves.” Common Core was not mentioned — only talk of his passion for education reform. As strong a case as he made for conservative economics, immigration and Common Core are still going to be two of his main hurdles to get over, especially when his fellow Republicans come after him on them on the trail and in primary debates. It’s no secret that Bush has been pro-immigration reform, but now that he’s out there, his past comments will be highlighted and scrutinized by the base in ways they haven’t been before. Case in point, the leak of his 2013 comments, in which he said that for so-called DREAM-ers, children brought to the U.S. illegally: “[I]t’s ridiculous to think that there shouldn’t be some accelerated path to citizenship.” And he implied that cities like Detroit should once again be re-populated by immigrants.

Scott Walker, the new front runner: With all the talk of Jeb Bush — and, don’t get us wrong, his donor network, last name and seriousness no doubt make him top tier — there’s a new front runner in the GOP race. Wisconsin Gov. Scott Walker now leads in polls in both Iowa AND New Hampshire. A poll out Wednesday shows Walker leading Bush 21 to 14 percent with Rand Paul and Ben Carson next at 8 percent, Chris Christie and Huckabee 7 percent, Marco Rubio 5 percent, Ted Cruz and Rick Perry at just 3 percent. Take the poll with a heavy grain of salt, though. It’s an automated poll, and it’s very early. There’s going to be a lot of volatility. But it’s at least notable that the trend in this poll shows movement in Walker’s favor. Before Romney dropped out (before getting in), Romney led with 29 percent, Bush pulled in 11 percent, and Walker was at just 8 percent.

Daily Presidential Trivia: On this day in 1937, President Franklin Roosevelt proposed enlarging the U.S. Supreme Court. FDR’s proposal did not succeed, but he did appoint a record number of justices to the court. How many Supreme Court justices did Roosevelt appoint? Be the first to tweet us the correct answer using #PoliticsTrivia and you’ll get a Morning Line shout-out. Congratulations to roy wait ‏(@ind22rxw) for guessing Wednesday’s trivia: How many states cast electoral votes in the first election (bonus: which ones)? The answer: 10- Connecticut, Delaware, Georgia, Maryland, Massachusetts, New Hampshire, New Jersey, Pennsylvania, South Carolina and Virginia.

2016:

LINE ITEMS

TOP TWEETS

In case you were wondering, yes, @kcbecker is indeed wearing IUD-shaped bling in honor of her contracep. bill #coleg pic.twitter.com/bYcKUXxrJm — Megan Verlee (@CPRverlee) January 30, 2015

This guy was too busy texting to see the humpback whale right in front of him: http://t.co/IIMb6qcq8b pic.twitter.com/VaR8eIW2Xv — World News Tonight (@WNTonight) February 4, 2015

My congressional office always had more of an unintentional Antiques Roadshow kind of decor to it, really. — John Dingell (@JohnDingell) February 3, 2015

Says the man running for president… RT @ZekeJMiller: Jeb: “Run for governor, because it’s the best job in the world” — Matt Viser (@mviser) February 4, 2015

For more political coverage, visit our politics page. Sign up here to receive the Morning Line in your inbox every morning. Questions or comments? Email Domenico Montanaro at dmontanaro-at-newshour-dot-org or Rachel Wellford at rwellford-at-newshour-dot-org. Follow the politics team on Twitter: Follow @DomenicoPBS

Follow @elizsummers

Follow @rachelwellford

Follow @sfpathe