Primaries in 5 states will help determine if GOP can keep control of Congress and block impeachment of Trump

Voters in Maine, Nevada, North Dakota, South Carolina and Virginia were casting ballots Tuesday to pick candidates for the Nov. 6 general election for the U.S. Senate and House, governor and other state offices.

There are a number of things to watch for, including the first statewide test of a “ranked-choice” ballot in Maine, as the candidates who will help determine which party controls the House and Senate in the next Congress.

The future of the Trump agenda will be at stake in November. If Republicans continue to keep their majorities in the House and Senate we can expect more tax cuts to be proposed, continued deregulation of businesses to benefit the economy, and actions designed to cut the U.S. trade deficit with other nations.

If, on the other hand, the Democrats gain majority control of the House and possibly the Senate (a less likely occurrence), the first thing on the agenda is likely to be an effort to impeach President Trump, along with votes for higher taxes, new gun-control measures, and the re-regulation of the Internet as a public utility.

The best shot Democrats have to do well in November will be to nominate moderate, mainstream candidates whose views are acceptable to independents. If they capture control of the House, Democrats are likely to elect Minority Leader Nancy Pelosi of California – a sharp antagonist of President Trump – to once again become speaker.

Here’s a look at primaries in the five states voting Tuesday:

MAINE

Voters picking nominees for governor, U.S. Senate and the U.S. House were using a “rank choice” system for the first time. Under this system, voters cast their preference for candidates in order underneath their first choice. These rankings will be considered (if there are more than two candidates in the race) in calculating the eventual nominees.

At the same time, voters were being asked to cast ballots on whether this rather bizarre system is kept in place for future elections, to prevent any candidate from winning an election without the support of at least 50 percent of the electorate. Retiring Republican Gov. Paul LePage was elected twice without winning the support of a majority of voters.

There are seven Democrats and four Republicans seeking their party’s nomination to succeed LePage, meaning it is unlikely the nominees in either party will be known for several days because of the “rank choice” system.

In the state’s 2nd Congressional District, which covers the northern part of the state, Republican U.S. Rep. Bruce Poliquin will face off against one of three Democrats in a district Donald Trump carried for president in 2016.

NEVADA

Both parties have contested races for the nomination to succeed retiring Republican Gov. Brian Sandoval, who is term-limited.

On the GOP side, the field of eight is likely to come down to either state Attorney General Adam Paul Laxalt, the grandson of GOP Gov. and U.S. Sen. Paul Laxalt, and State Treasurer Dan Schwartz.

Among the six Democrats on the ballot, the contest for the nomination appears to come down to a choice between Clark County Commissioners Chris Giunchigliani, who’s backed by Hillary Clinton, and Steve Sisolak.

In the race for U.S. Senate, the Democrats are likely to nominate first-term U.S. Rep. Jacky Rosen to go up against GOP incumbent Sen. Dean Heller, considered by many to be the most endangered of the Republican senators seeking re-election in November.

In the House, most of the attention is on the state’s open 3rd and 4th Congressional Districts. In the 3rd District, which is mostly comprised of areas of Clark County outside Las Vegas, the GOP frontrunner is Danny Tarkanian, son of the legendary University of Nevada, Las Vegas basketball coach, who died in 2015.

Danny Tarkanian was “nudged” out of the Senate primary into the race through a personal appeal from President Trump.

Leading the field of Democrats is Susie Lee, who has Rep. Rosen’s support as well as former Senate Democratic Leader Harry Reid’s and former Vice President Joe Biden’s.

In the 4th District, a largely rural expanse that covers the middle part of the state, former GOP U.S. Rep. Crescent Hardy and former Democratic U.S. Rep. Steven Horsford look most likely to advance to the general election.

NORTH DAKOTA

The November election for U.S. Senate should be one of the most competitive in the nation. It will most likely pit Democratic incumbent Heidi Heitkamp, who is seeking a second term, against the state’s lone member in the U.S. House, Republican Kevin Kramer.

Heitkamp won six years ago with just over 50 percent of the vote, while Kramer was re-elected in 2016 with 69 percent, President Trump carried the state by a double-digit margin in 2016.

In the race to replace Kramer, Democrat Mac Schneider will face off against whichever Republican emerges from a field of four seeking the GOP nomination Tuesday.

SOUTH CAROLINA

President Trump is on the GOP ballot by proxy in several Republican primary contests in the Palmetto State.

In the race for governor, Republican incumbent Henry McMaster – who got the job after the president picked then-Gov. Nikki Haley to be U.S. ambassador to the United Nations – sits atop a field of five.

As lieutenant governor McMaster was one of the earliest statewide officials to endorse Donald Trump for president in a state where the GOP presidential primary comes early and is critical.

Late polling suggests McMaster could end up in a runoff against either state Rep. Catherine Templeton or businessman John Warren, with the winner going on to face one of three Democrats seeking the nomination.

President Trump is also on the ballot by proxy in the state’s 1st Congressional District – consisting mostly of the city of Charleston. Former governor and incumbent GOP U.S. Rep. Mark Sanford, who many consider a “Never Trumper,” – is being challenged largely because of his perceived lack of support for the president – by GOP state Rep. Katie Arrington.

In the open 4th Congressional District, a crowded field of Republicans and Democrats are competing for the nomination for a seat generally believed to be firmly in the Republican column in the fall election.

VIRGINIA

Democrat U.S. Sen. Tim Kaine, who was Hillary Clinton’s running mate in 2016, is unchallenged for renomination. He will face off in the general election against the winner of the Republican primary, which pits Prince William County Board Chairman and failed gubernatorial candidate Corey Stewart against State Rep. Nick Freitas and Bishop E.W. Jackson.

In the House there are a surprising number of competitive primaries, including the one in the states 10th Congressional District, which runs from the Washington suburbs out into the middle of the state.

On the GOP side, Republican incumbent Barbara Comstock is trying to dodge attacks launched by Shak Hill, a former U.S. Air Force officer who’s never held office in Virginia. Whoever wins the GOP primary goes on to the general election against one of seven Democrats competing for the nomination in a district carried by Hillary Clinton by almost 10 points.

In the 2nd District in the Virginia Beach area, a surprising contest has developed between first-term Republican and former Navy SEAL Scott Taylor and Mary Jones, a local activist whose agenda closely mirrors President Trump’s in many ways.

The possibility of an upset here makes the outcome of the Democratic primary between retired Navy Cmdr. Elaine Luria and teacher Karen Mallard another race to watch because of the large number of active and retired military members who live in the district.

Washington-based commentator Peter Roff is former senior political writer for United Press International and former contributing editor for opinion at U.S. News and World Report.