House Speaker Paul D. Ryan (R-Wis.) meets with reporters on Capitol Hill on March 2. (J. Scott Applewhite/AP)

With each passing day, House Speaker Paul D. Ryan gets more confident that his troops are falling in line and that they will soon pass legislation repealing the Affordable Care Act.

“I am perfectly confident that when it’s all said and done, we are going to unify,” Ryan (R-Wis.) told reporters Thursday. “Because we all — every Republican — ran on repealing and replacing [the ACA]. And we are going to keep our promises.”

Yet over in the Senate, Majority Leader Mitch McConnell (R-Ky.) is much more circumspect. “The goal is for the administration, the House and the Senate to be in the same place,” McConnell told reporters Tuesday. “We’re not there yet.”

This is the way it used to work, back before the rabble-rousing tea party turned Republican politics upside down. Whether Republicans or Democrats were running Congress, the biggest hurdle for many decades was always getting legislation through the cumbersome rules of the Senate, with all the rights afforded to the minority party there.

For the past six years, however, that dynamic has been turned on its head. Instead, the House Republican Conference has functioned somewhere between a junior high school class with a substitute teacher and a failed nation state.

Time and time again, McConnell would draw up a scheme for Republicans to score some small victory against the Obama administration, or even to just avert a complete fiscal disaster. Then House Republicans would fall apart, unable to muster the votes for McConnell’s plan, losing all GOP leverage and ending the impasse on Democratic terms.

The 2013 government shutdown, under then-Speaker John A. Boehner’s watch, epitomized this dynamic. Then in the fall of 2015, hard-line conservatives refused to pass a spending bill with funding for Planned Parenthood, forcing Boehner (R-Ohio) to resign as speaker. Even after Ryan took the gavel, the House GOP struggled to accomplish basic tasks such as passing the annual budget.

Now, however, the tide might be shifting back to its normal course. Ryan and his top lieutenants are increasingly optimistic they will have the votes to pass their version of legislation to repeal the health-care law and replace some elements of it.

There are still holdouts among Ryan’s caucus, particularly the more than 30 members of the House Freedom Caucus who make up the most conservative group and who helped drive Boehner out of office. But Ryan has a much bigger margin of error than McConnell. With 431 House members, Ryan can afford to lose only 22 of the 238 Republicans and still pass the legislation on the slimmest of majorities.

In the Senate, under special budget rules allowing a simple majority for the repeal effort, McConnell can lose just two GOP senators and then use Vice President Pence to cast the tiebreaking vote to get the legislation to President Trump’s desk.

Sen. Susan Collins (R-Maine), a leading moderate, might oppose the legislation because it would revoke Planned Parenthood funding, and a bloc of conservatives is threatening to vote no because Ryan’s emerging bill relies on new tax credits to help consumers buy health insurance. Some big-state Republicans worry that the House bill would leave millions of their constituents without health care because of its approach to the expansion of Medicaid that took place in their states after the ACA became law.

“It’s just a very narrow path,” Sen. Roy Blunt (R-Mo.), a junior member of McConnell’s leadership team, said Thursday.

Elected statewide, senators are traditionally tougher to roll over in pressure campaigns. They tend to act as if they’re each their own separate business entity, with a bigger profile than their House counterparts.

Before winning his Senate seat in 2010, Blunt spent six years in the majority whip operation for House Republicans during an era in which they basically succeeded on every vote.

One reason for that success, Blunt said, was the presence of President George W. Bush in the White House. During every close vote, the Republican whip team could pressure wavering lawmakers by telling them that their opposition would block something from becoming law.

In recent years, with a Democrat in the Oval Office, rank-and-file Republicans felt free to oppose Boehner and Ryan because the legislation passed by the House often served as a symbolic stand or an opening ante in a negotiation that seemed destined to tilt toward Democrats.

“It was a totally different ask,” Blunt explained, comparing the two eras.

There are some signs that House Republicans will be far more fearful of opposing Ryan — and Trump, should the president fully embrace the speaker’s plan in the weeks ahead.

“I think they’re in a different environment,” Blunt said.

So now Ryan is essentially daring his right flank to blow up the chance to actually repeal a law that they’ve been vowing to impale for seven years now.

“We have been running on repealing and replacing Obamacare since 2010,” the speaker said Thursday, pointing to legislation that was crafted in recent years by Tom Price in the House, before he was confirmed last month as Trump’s secretary of health and human services. “That is the bill, the plan that we ran on in 2016. We told America, ‘Here is our vision for how we replace Obamacare after we repeal Obamacare.’ That’s the bill we’re working on right now.”

It remains to be seen whether McConnell has as much confidence as Ryan.

Read more from Paul Kane’s archive, follow him on Twitter or subscribe to his updates on Facebook.