Rep. Paul Ryan (R-Wis.), left, walks with House Speaker John A. Boehner (R-Ohio) as he returns to Capitol Hill to vote on a stopgap spending bill. (J. Scott Applewhite/AP)

GOP vice-presidential nominee Paul Ryan returned to Capitol Hill to mixed reviews Thursday, entering the House floor to loud cheers and a standing ovation from his Republican colleagues, while Democrats tried to use Ryan’s new celebrity against him.

They took the opportunity to attack the congressman from Wisconsin and the policy proposals he has come to represent.

Ryan, the House GOP’s budget guru and most prominent policy thinker, had missed all 19 House votes since he was chosen as Mitt Romney’s running mate last month. On Thursday, he came back to vote on a series of routine bills, which reunited him with his biggest admirers — House conservatives.

But there was no joint news conference. No embrace on the Capitol steps. The hugs happened in private, and in the camera-free zone of the House floor.

It was as if the candidate and his adoring colleagues — for all their mutual admiration — weren’t sure about being photographed together.

“Great to be here,” Ryan said, when asked what it was like to be back in the place where he started his career as a staffer.

Ryan’s return should have been a moment of celebration. By selecting the House Budget Committee chairman as his running mate, Romney affirmed the House Republicans as keepers of the GOP idea.

But, in the risk-averse environment of a campaign, there were also good reasons for Ryan and his colleagues to avoid one another.

A close association with Ryan could make trouble for some members in tight reelection campaigns. The cornerstone of Ryan’s budget proposals, a plan to restructure Medicare for future recipients, is widely unpopular. And a close association with congressional Republicans might not be helpful for Ryan, either. In one late August poll, two-thirds of respondents disapproved of their job performance.

That was only one of the reasons why it was odd that Ryan came back, taking a valuable day off from the campaign trail.

Another one was tradition. Usually, running mates plucked out of Congress tend not to come back.

That was the case in 2000 for Sen. Joseph I. Lieberman (I-Conn.), and in 2004 for then-Sen. John Edwards (D-N.C.). Both missed every Senate vote, returning only after the campaign was over. In 2008, when the two presidential tickets included three senators, the trio of Barack Obama (D-Ill.), Joseph R. Biden Jr. (D-Del.) and John S. McCain (R-Ariz.) came back for just one vote — to approve a massive bailout for the country’s teetering banks.

On Thursday, Ryan came back for less-dramatic business, H.J. Res. 117, a bill to keep the government running through March.

Ryan’s vote wasn’t needed. The bill was expected to pass easily, and did, 329 to 91. Ryan was a “yes.”

Inside the Capitol, the people giving speeches about Ryan were generally not his GOP colleagues. They were Democrats and they were not being nice.

Sen. John D. Rockefeller IV (D-W.Va.) spoke about Ryan’s ambitious budget, which would slash tax rates and restructure Medicare. “I, for one, have been ashamed of this document,” Rockefeller said. Sen. Charles E. Schumer (D-N.Y.) said Ryan’s policies favored the rich and hurt the middle class: “It’s nice to see Paul Ryan back here in Congress. It’ll be even nicer to see him back here as a full-time member in January.”

GOP lawmakers reported later that Ryan talked about how his life had changed on the campaign trail, marveling that he hadn’t driven a car in a month. Others teased the famously fitness-obsessed Ryan about looking soft.

“It proves that the House isn’t a dead-end job,” quipped Rep. Blake Farenthold (R-Tex.) as he left. He said Ryan asked him about his own campaign this fall. “I still felt like it was Paul and not Vice President Ryan.”

After that, Ryan at last made a public appearance with another member of Congress, House Speaker John A. Boehner (R-Ohio). That appearance was required by Capitol geography: The two had to use a public hallway to reach the House floor, so Ryan could vote.

“Speaker Boehner, what’s it like to be second fiddle?” a reporter asked as they went, other top House Republicans trailing behind. The speaker laughed. “It’s just fine,” he said.

Ryan is unlikely to come back anytime soon. And even his colleagues think that’s a good idea.

“I’m glad he’s coming by to say hi to everybody before the vote. My message to him is, ‘Get out of here! Get outof here!’ ” said Rep. Jason Chaffetz (R-Utah). “We don’t need you here. We need you in Iowa or Florida or something!”