In the past two weeks, as the bipartisan Senate immigration bill was unveiled, he has continued to do the heavy lifting with conservatives in an attempt, at best, to win their support or, at least, to convince them to keep an open mind.

The most striking thing about the political debate over immigration in 2013 and how it differs from what we saw during the McCain-Kennedy bill debate in 2007 is the reduced intensity of the opposition.

Perhaps political reality has set in. Perhaps times have changed and immigration has received less attention than other issues like national security and the economy and debt issues.

Or perhaps the opponents of any earned path to legalization are fewer and less vocal.

The most significant factor in changing the fortunes of immigration reform is the leadership of Rubio, who has single-handedly given conservative credibility to this approach, which was unthinkable during the McCain-Kennedy days.

McCain-Kennedy was a vastly different bill than what has been proposed here. Conditional legal status begins when the bill is signed, but that “status” differs only slightly from the de facto amnesty of our current system.

The opportunity to apply for a visa begins at the 10-year mark, and the process for earned citizenship begins, if the border security triggers are met, no sooner than 13 years after enactment, and only once the 4.8 million people already waiting in line are processed. For this trade-off, Republicans get the most serious border security effort in American history, implementation of the E-verify system for all employers, an improved legal immigration system and a temporary worker program for specific industries that need one.

The Rubio plan needs two things: improvement and momentum.

In an important floor speech on the bill on April 18, Sen. Rubio made clear that the bipartisan Senate bill is a starting point, not a take-it-or-leave-it bill. He asked every member, even those who may end up opposing it, to help improve the border security provisions.

This approach invites all senators to help, rather than making them reflexively defensive about the Gang of Eight’s behind-closed-doors meetings.

What are the political prospects for immigration this year?

In the Senate, the Judiciary Committee began hearings on the bill last week and will mark it up after this week’s recess. The markup will be interesting, as Sens. Ted CruzRafael (Ted) Edward CruzOvernight Health Care: Trump eases rules on insurance outside ObamaCare | HHS office on religious rights gets 300 complaints in a month | GOP chair eyes opioid bill vote by Memorial Day HHS official put on leave amid probe into social media posts Trump, Pence to address CPAC this week MORE (R-Texas), John CornynJohn CornynLawmakers feel pressure on guns Kasich’s campaign website tones down gun language after Florida shooting Murphy: Trump’s support for background check bill shows gun politics ‘shifting rapidly’ MORE (R-Texas), Mike LeeMichael (Mike) Shumway LeeThe 14 GOP senators who voted against Trump’s immigration framework Prison sentencing bill advances over Sessions objections Grassley ‘incensed’ by Sessions criticism of proposed sentencing reform legislation MORE (R-Utah) and ranking member Jeff SessionsJefferson (Jeff) Beauregard SessionsUnder pressure, Trump shifts blame for Russia intrusion Overnight Tech: Judge blocks AT&T request for DOJ communications | Facebook VP apologizes for tweets about Mueller probe | Tech wants Treasury to fight EU tax proposal Overnight Regulation: Trump to take steps to ban bump stocks | Trump eases rules on insurance sold outside of ObamaCare | FCC to officially rescind net neutrality Thursday | Obama EPA chief: Reg rollback won't stand MORE (R-Ala.) will offer stronger border security language.

Ultimately, the bill has enough votes to get out of committee, with all of the Democrats and at least three Republicans approving it: likely to be Sens. Orrin HatchOrrin Grant HatchOvernight Finance: NAFTA defenders dig in | Tech pushes Treasury to fight EU on taxes | AT&T faces setback in merger trial | Dems make new case against Trump tax law | Trump fuels fight over gas tax What sort of senator will Mitt Romney be? Not a backbencher, even day one Lawmaker interest in NAFTA intensifies amid Trump moves MORE (R-Utah), Lindsey GrahamLindsey Olin GrahamCongress punts fight over Dreamers to March Pence tours Rio Grande between US and Mexico GOP looks for Plan B after failure of immigration measures MORE (R-S.C.) and bill co-author Jeff FlakeJeffrey (Jeff) Lane FlakeFlake to try to force vote on DACA stopgap plan Congress punts fight over Dreamers to March Outgoing GOP rep: Republican Party 'heading into trouble' in election MORE (R-Ariz.).

The full Senate will consider the bill over a period of weeks before the July 4 recess. While some will offer “poison pill” amendments, sincere efforts to improve the bill will only add to its eventual support and minimize the strength of those who remain opposed.

I believe the most likely scenario is Senate passage with at least 70 votes in late June.

The House is important for two reasons.

First, they may dim the Senate bill’s hopes if they demonstrate adamant majority opposition to any earned path to citizenship, something I suspect will not occur. Second, they must pass something.

The House will use regular order and likely advance individual bills dealing with individual provisions, giving members the opportunity to support or oppose each as they see fit, rather than be asked to swallow an entire reform bill.

While the process in the House, which initially will be led by House Judiciary Committee Chairman Bob GoodlatteRobert (Bob) William GoodlatteProgressive group targets GOP moderates on immigration Florida shooting reopens CDC gun research debate Congress punts fight over Dreamers to March MORE (R-Va.), will be both fascinating and good theater, from a legislative standpoint, all that matters is that they pass something. The Senate needs a House vehicle so the two bodies can get to a conference committee to hammer out one version.

The timing of this is unpredictable, but ultimately I expect Congress will be asked to approve a compromise, comprehensive bill by year’s end. Next year is a campaign year for the House and one-third of the Senate, and in reality a thorny issue like this cannot be dealt with in good faith in a campaign year.

The immigration issue is likely to dominate the political news for much of the next two months, but the likely result is that at the end of an intense period, the Senate will pass the Rubio plan and the House will pass something, making final passage more likely by year’s end.

Matt Mackowiak is an Austin, Texas, and Washington-based Republican consultant and president of Potomac Strategy Group, LLC. He has been an adviser to two U.S. senators and a governor, and has advised federal and state political campaigns across the country.