(CNN) The investigation into Russia's meddling with the US election last year and increasing pressure to reach a final deal on repealing and replacing Obamacare are at the top of Congress' agenda next week.

Members of Congress will also find out who will represent Georgia's sixth congressional district after a high-profile special election Tuesday. And the legislative branch as a whole is still reeling from a targeted shooting last Wednesday , which hospitalized Rep. Steve Scalise.

Here's your guide to the biggest issues of the week:

Russia investigation continues in both chambers

Both House and Senate intelligence committees have hearings scheduled this week, as Capitol Hill investigators continue to call in witnesses and await requests for materials in the probe of Russia's involvement in the 2016 election.

On Wednesday the Senate intelligence committee holds an open hearing featuring cybersecurity and state election officials focused on potential threats to the 2018 and 2020 elections by Russian operatives.

Former Homeland Security Secretary Jeh Johnson testifies on Russia before the House intelligence panel Wednesday. He met with the Senate committee in a closed session already.

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Health care reaches another do-or-die moment

It's another critical week for the Republican push to repeal and replace Obamacare in the Senate . Leaders have already blown through their self-imposed deadline to get legislative text to the Congressional Budget Office ahead of a vote on the floor. Details on what's in the Senate version are closely held, and even senators on committees tasked with crafting the bill are having trouble finding out what's in the deal.

Senate Majority Leader Mitch McConnell continues to aim for a Senate floor vote before the July 4 recess.

In a tweak at the GOP's closed door process, Senate Minority Leader Chuck Schumer called for a bipartisan all-Senators meeting on health care in the Old Senate Chamber on Friday, but it's clear from McConnell's office they weren't making that happen.

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Capitol Hill watching Georgia special election

The most expensive election for a House seat takes place Tuesday, when Republican Karen Handel faces Democrat Jon Ossoff to fill the vacancy left when former Rep. Tom Price took the position of Health and Human Services secretary.

The suburban Atlanta district, which in recent elections has been considered reliably Republican, is being viewed as a bellwether for the 2018 midterm elections.

Republicans are already pointing out Ossoff's substantial financial advantage -- he has raised more than $23 million. Both parties and outside groups have funneled millions into the race and high profile surrogates have worked to rally their supporters.

Tax reform

House Speaker Paul Ryan is giving a major speech on tax reform Tuesday at the National Association of Manufacturers.

The address comes a year after the House GOP unveiled their principles, but the party continues to struggle to come up with legislation because of internal divisions over Ryan's preferred plan to pay for the bill using the border adjustment tax . Ryan, along with McConnell, continues to meet regularly with top Trump Administration officials and the chairs of the tax writing committees to reach a deal, but no detail are expected to be unveiled in his speech.

Serious splits among defense hawks, conservatives, appropriators and centrists are making the effort to cobble together a Republican budget difficult. Leaders are pressing members to come to consensus so they can use reconciliation to push the GOP tax reform plan through the Senate with a simple majority.

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The House Budget Committee was aiming to mark up a proposal this week, but hurdles remain inside that panel with several House Freedom Caucus members demanding a guarantee of spending cuts to be made part of the final deal. A final GOP fiscal blueprint is not expected until the last week in June, which means the House won't vote on the budget until after the week long July 4 recess.

Security after Scalise attacked

Scalise remains hospitalized in serious condition after being shot in a targeted attack on the GOP baseball team which was practicing at a field in Alexandria, Virginia, last Wednesday morning.

One of his physicians briefed reporters Friday and said Scalise' condition has improved, noting when he arrived at the hospital "he was as critical as you can be." He predicted that he will remain in the hospital for "a considerable period of time."

Following last week's shooting there is still anxiety among members of both parties about their personal security. Leaders are discussing ways to increase money for lawmakers' increased security costs, and are trying to navigate pressure from some to boost taxpayer funding for official office budgets for these purposes.

Following last week's Congressional Baseball Game that celebrated unity, the Congressional Women's Softball Game is scheduled for Wednesday night. This time both Democrats and Republican women team up to take on members of the Capitol Hill press corps for a charity game to benefit breast cancer research.

The body-slamming politician is sworn in and other notable events this week

Montana Republican Rep.-elect Greg Gianforte is expected to be sworn in next week on the House floor to fill the vacant seat of former Rep. Ryan Zinke, who is now Secretary of the Interior.

Gianforte gained national attention in May when he assaulted Ben Jacobs, a reporter for the Guardian, who was attempting to ask him about the GOP health care bill the day before the special election.

The Senate will vote Monday on the nomination of Brock Long to be administrator of the Federal Emergency Management Administration.

After the Trump Administration's focus last week on workforce and education issues the House will vote on several bills focused on closing the skills gap. There will also be vote on bipartisan measures focused on improving the foster care system.

Interior Secretary Zinke will sit before the energy and natural resources committee Tuesday to talk about budget requests for the Interior Department. He will also go before the appropriations committee the next day.

Also Tuesday, the foreign relations committee will hold a hearing on reviewing Congressional authorizations for the use of military force, an issue that hasn't seen much attention since the US launched airstrikes in Syria this spring.

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And at the same time Congress has multiple investigations into whether the Trump campaign colluded with Russia, a judiciary subcommittee on crime and terrorism will host a hearing Tuesday, "Concurrent Congressional and Criminal Investigations: Lessons from History."

On Wednesday, the commerce, science and transportation committee will meet Wednesday for a hearing with David Pekoske, Trump's nominee for the administrator of TSA.

Energy Secretary Rick Perry will testify before the House and Senate appropriations committees on the department's budget requests Tuesday and Wednesday and again before the energy and natural resources committee on Thursday.

Budget Director Mick Mulvaney will appear before the House appropriations committee Wednesday.