Washington (CNN) -- Briefly back in Congress doing his day job, Ron Paul met with high school students outside his office.
True to form, he signed copies of the Constitution and wryly told them with a chuckle, "No one around here reads it very much. I'd like to get everybody to read it."
Paul made a detour from the presidential campaign trail to Capitol Hill on Wednesday in order to cast a vote to protest raising the debt limit.
"We are in denial here in Congress," Paul said on the House floor. "If we had the vaguest idea of how serious this crisis is financially, not only for us but for the world, we would cut spending."
The busy Texas Republican lawmaker seemed to cram in as much as he could to push his libertarian agenda -- even introducing legislation to repeal indefinite detention of terror suspects he calls unconstitutional.
What Paul did not do was attend a closed-door gathering of House Republicans. In fact, the GOP presidential contender is known to never attend these meetings.
But Paul's Republican colleagues who did go had no shortage of opinions about his strong showing in the presidential race so far.
Many were good.
"You've got to admire an individual who, despite the currents of the time -- polling data -- says what he believes in and sticks to it. Ron Paul does that," said Rep. Mo Brooks, R-Alabama, who has served with Paul for years.
"The public understands we have too many Monty Halls and Bob Barkers wanting to make a deal or 'the price is right' in Washington, D.C., and they're yearning for leadership -- people who take a position and stick to it," Brooks said.
Rep. Kevin Brady, Paul's fellow Texan, said he disagrees with Paul on many issues but isn't surprised about his success in these tough economic times.
"He's been so consistent over the years. He feels very strongly about limited government, about personal responsibility and individual freedoms, and staying consistent has drawn a good, solid base for him in this presidential campaign," Brady said.
Other House Republicans were less positive about Paul's ascent.
"I don't have any personal dislike for the man, but I will say to you that he has really been essentially totally ineffective in Congress," said Rep. Trent Franks, R-Arizona.
Franks, who has endorsed Newt Gingrich, called Paul a "nonplayer" on Capitol Hill.
"That's why most of his supporters support him, but what they don't realize is that most of the things he puts forward are only for the consumption of the public," Franks said.
From government spending to military action abroad, Paul has spent decades building a reputation that earned him a nickname inside the GOP leadership: Doctor No.
"He voted no on absolutely everything," said John Feehery, a veteran House Republican leadership aide who worked for former House Speaker Dennis Hastert and House Majority Leader Tom DeLay.
"We didn't count on him for anything. In many ways, he was an ideological warrior," Feehery said.
"Many times, the vote would be 434-1 -- he'd be the one, but he was the one who kind of put up the ideological goal posts -- this is where you should be if you're pure, and what we found is no one is really pure except Ron Paul," he said.
Several House Republicans told CNN they admire his purism.
"Dr. No puts up his vote, and if you want to know why, he tells you why. And if you want to vote with him, great, and there's been a lot to be said for it," said Rep. Darrell Issa, R-California, who says he personally likes Paul very much.
But Issa is one of several Paul legislative colleagues who say that his refusal to compromise often goes too far.
"Ron Paul is less like a Ronald Reagan and more like somebody who is a great professor but you wouldn't want to have him run your company," Issa said.
So far, 64 members of Congress have endorsed Mitt Romney. Just three have endorsed Paul, the only sitting lawmaker in the race. One is Paul's son Rand, a senator from Kentucky. Another is Paul's good friend Walter Jones, a fellow anti-war Republican.
"I like Ron Paul's independence," Jones told CNN in his office. "He knows we've got to fix the problems of the American people. We've got to fix the job situation. We've got to bring this debt down, and I think he is exactly what America needs right now."
Jones has supported Paul for years and watched him extolling the importance of less involvement abroad, smaller government and greater personal liberties without finding mass appeal.
Jones thinks Paul has caught fire now because he has been so consistent.
"They trust him," Jones said.
Paul has a reputation in Congress as a loner. But Jones dismisses that by revealing a mock picture he displays in his office of Paul with congressional friends, dressed as the singing group The Four Tops.
"It's a great picture of him," jokes Jones. "He's got the look of a president."
But Paul's good friend from North Carolina does concede that "he's just not a socialite."
"He's a workhorse, and that's what Washington needs right now is a workhorse, not a show horse," Jones said.
He also warned that even if Paul isn't the nominee, the Republican Party needs to listen to him and show respect or risk losing the opportunity to capture some of Paul's supporters who are young and independent.
"He brings a support base that is so truly committed to his points of views and his issues that if the party doesn't find a way to bring Ron Paul in, I don't think he's going to do anything outside of it, but he won't be very helpful."